The Logical Form of Omission Sentences

The Logical Form of Omission Sentences

There is an undeniable appeal to Davidson’s treatment of action sentences, in which adverbs appear as predicates of events quantified over.[1] Thus “John buttered some toast quickly in the kitchen” becomes “There was an event esuch that e was a buttering and e was by John and e was quick and e was in the kitchen”. Events have properties and action sentences ascribe these properties to them by means of adverbs. The underlying logical form is the familiar pattern of existential quantification plus conjunction. But what about omission sentences such as “John omitted to butter some toast quickly in the kitchen”? Suppose you instruct John to do just that and he agrees, but then he neglects to perform the action in question: the quoted sentence then expresses a truth. There are omissions as well as actions. Can we render that sentence in Davidson’s style? This would read: “There was an event e such that e was an omission of buttering and e was by John and e was quick and e was in the kitchen”. But none of that is true: there was no such event and it certainly wasn’t quick and in the kitchen. Nor can we say, “There was an omission o such that o was a buttering etc.”: even if we are willing to quantify over omissions, it sounds wrong to say that the omission in question was quick and in the kitchen. How can omitted actions have properties? They didn’t occur, so how can they be one way rather than another? Neither would it be correct to take the omission sentence as simply the negation of the corresponding action sentence, as in “It is not the case that John buttered some toast quickly in the kitchen”. That sentence does not entail that there was any omission on John’s part, but simply that he didn’t perform a certain action—it is clearly not true that whenever we don’t do something we omit to do that thing. One’s life is not full of omissions corresponding to all the actions we don’t perform. The problem, evidently, is that omissions are not events with properties, which is what Davidson’s analysis calls for. Accordingly, omission sentences don’t have the logical form of action sentences, so the adverbs appearing in them are not functioning as predicates of events. But further, action sentences and omission sentences have the same syntax, both containing adverbs, in which case it is hard to see how action sentences can have Davidson’s logical form either. Any action sentence can be converted into an omission sentence simply by inserting “omitted to” before the action verb, so the two must clearly share their semantics. Therefore action sentences don’t have the logical form of quantification plus conjunction. What logical form they do have is another question.

[1] See “The Logical Form of Action Sentences”.


Epiphenomenal Facts

Epiphenomenal Facts

Epiphenomenalism is the doctrine that mental facts (properties, events, states) are causally idle. When it seems as if mental facts are causing behavior it is really correlated neural facts that are doing the causing—electrical signals sent from the brain down the efferent nerves and into the muscles. This is taken to be a singular fact about the mental: it is uniquely lacking in causal powers. Even in the case of a steam engine emitting waste steam—the standard analogy for epiphenomenalism—the steam can cause something, possibly burns in someone too close to it. The mental is thought exceptionally idle, and this is taken by many to be an objection to epiphenomenalism—too much of an anomaly. But is that true—are there no other epiphenomenal facts in the world? In fact, they seem quite plentiful upon closer examination. Obvious examples would be mathematical and ethical facts: they don’t cause anything either, but they are real. Nor is this merely contingent: it is intrinsic to such facts that causality be foreign to them. The same is true of such properties as identity, existence, necessity, and set membership—none of these feature in causal explanations or confer causal powers. Ditto for logical properties such as entailment and validity: these have no causal consequences either. Does the property of being a cause itself have causal consequences? Nope. These may be thought rather abstract properties, unlike mental properties, but we can easily find more concrete properties that likewise fail of causal potential. Colors are an obvious example: colors don’t cause anything either—only their underlying physical correlates do. If colors are projected onto the world, it is predictable that they make no difference to the causal powers of the objects onto which they are projected—subtract them and the object remains causally indistinguishabe. This is why mechanics makes no mention of colors in its theories of motion (red balls move the same way as blue balls). Acceleration and mass affect the causal powers of bodies, but not color (or taste etc.). Epiphenomenalism is all around us.

            And it doesn’t end there. Do space and time have causal powers? Not inherently—not independently of material objects (even in Einstein’s General Relativity). Does infinity have causal powers? Does the infinite divisibility of space and time show up in the causal powers of things? Would it make any difference to the causal workings of the world if they were finite? It is not clear that it would. Is it even clear that geometrical forms have causal powers? Does it really make a difference to how objects behave whether they instantiate perfect circles? Causality is not fine-grained enough to care whether objects are platonically perfect. Causal powers in the physical world stem from four underlying forces: gravity, electromagnetic force, the strong force, and the weak force. But these operate independently of the geometrical and chromatic properties of objects: being a perfect circle (or an imperfect one), or being a whiter shade of pale, are not their concern. Mass matters, for sure, but not platonic forms or visual appearances. Of course, it matters whether an object is circular or rectangular in the vernacular sense, but not its fine-grained geometry. This is too abstract and ideal to be of concern to the rough and tumble of causality. In fact, objects don’t instantiate perfect platonic forms, though they do approximate to them, but it wouldn’t make any causal difference if they did.[1]

            This is all before we get to such peculiar properties as being thought of by Bertrand Russell one Saturday afternoon. Whether an object has this property makes no difference to its causal potential. Nor does the property of being round and such that 1 +1 = 2. Nor does the property of having a counterpart in another possible world. These are all far too extrinsic to count as causal powers. But mental properties are not extrinsic, so shouldn’t they have causal powers? Let’s consider functional properties, e.g. having the function of pumping the blood. The heart has this property: is it causal? It is not: the heart doesn’t pump blood in virtue of having the function of doing so. It pumps blood in virtue of its elastic and propulsive properties—the properties that enable it to discharge the function it has. The heart could have that function and not have the power to pump blood (it’s a defective heart). No more does a lawn mower cut grass in virtue of having the function of mowing lawns—for that it needs sharp blades and forward momentum. Having a certain function is not part of the causal powers of an object; having the properties that carry out that function is. So we could say that functional properties are epiphenomenal: they are facts but not causal facts. Just so, an organism has many functional properties that are causally idle, corresponding to its various organs. The color of blood is epiphenomenal, but so is its function per se. Functions are not causes. Teleology is not causality. Nor is species membership a cause: being of a certain species is not something that makes a causal difference, not in itself. True, members of a species have the power to interbreed, but not in virtue of species membership—for that they need a certain kind of physiology. Properties that sit idly by are certainly correlated with hardworking causal properties—and this may mislead us into thinking that they are less than completely indolent—but closer inspection reveals that they are not as such causally active. The pattern is that epiphenomenal properties sit atop causal properties—as functional properties are embodied in causal properties without being identical to them. 

            This is the picture the epiphenomenalist envisages for the mental and the cerebral. Mental facts are strictly speaking epiphenomenal facts, but they are tightly correlated with causal machinery in the brain. Is this a plausible view of mental facts? In the case of factive mental states like knowledge it certainly seems true: whether a belief counts as a case of knowledge is irrelevant to its power to affect behavior—being true is not a causally relevant property (the same for whether a perceptual experience is veridical). Intuitively, factives are too extrinsic to function causally. But much the same holds for propositional content generally: even a bit of externalism will have the result that content is epiphenomenal.[2] And how could an abstract proposition contribute to the causal powers of a belief? The causal powers of beliefs evidently derive from underlying brain states, possibly of a syntactic nature (this is a familiar story). Beliefs as such don’t cause behavior, but only the correlates of belief; or if you like, beliefs have a causal aspect but they are not causal through and through. Thus intentionality generates epiphenomenal facts, which is not very surprising—being about something is not the kind of property that can get muscles to contract. More interesting is the property of subjectivity: is what it’s like subjectively epiphenomenal? To be a subjective state is to be such that the nature of the state can only be grasped from a single point of view, i.e. by a being that shares the state in question. Only perceivers of red can grasp what it’s like to see red. This is an epistemic property of a mental state: it can only be known in a certain way. But how could that property contribute to the causal powers of the state? How could the state cause behavior in virtue of being knowable only in a certain way? Maybe material objects can only be known about in a certain way, i.e. by perception, but that has no bearing on their causal operations—physics doesn’t care about such epistemic questions. So the subjectivity of mental states isn’t part of their causal profile—which means that what an experience is like for its possessor isn’t part of its causal profile. The fact that we can’t know what it’s like to be a bat doesn’t affect the causal powers of bat experience—it carries on causing bat behavior irrespective of what we can know. Presumably bat experiences cause bat behavior in virtue of various objective facts about the bat’s brain—electrochemical activity, as we now believe.[3] In one clear sense, then, consciousness is epiphenomenal—it doesn’t cause behavior in virtue of there being something it is like. Of course, we can truly say of a conscious experience that it caused an episode of behavior, because it has a cerebral aspect or correlate; but we can’t infer from this that its conscious aspect is itselfa causal power. That is, given that a conscious property is not identical to a brain property, it does not have causal powers. We can loosely report that an experience of red caused someone to move in a certain way, but we can’t mean that the subjective nature of the experience acted causally—only that an underlying physical correlate did. Logically, the case is like saying that the color red caused someone to see red: it is not the color as such that does the causing but only its physical correlate in the object. Colors themselves are epiphenomenal, but that doesn’t preclude the existence of a correlated causal sequence leading from object to experience. Similarly, conscious states are epiphenomenal, but that doesn’t preclude the existence of a correlated causal sequence leading from brain to behavior. After all, epiphenomenal facts are common in nature, as we noted, and consciousness simply follows suit. It is not anomalous in this respect but typical.

            This solves a difficult problem. If conscious states had intrinsic causal efficacy, then we would have causal over-determination, since brain states also cause behavior. Each would be sufficient to cause the behavior in question, which means the other cause is not necessary. It may appear that the only way out is to identify the conscious state and the brain state, thus committing ourselves to reductive materialism. But a viable epiphenomenalism allows us to avoid this result while not accepting causal over-determination: it is the brain state alone that is doing the causing—the conscious state sits idly by, serenely epiphenomenal. The conscious state is numerically distinct from the brain state and the brain state is the sole cause of the behavior—because the conscious state has no causal role to play in producing the behavior (not intrinsically and as such). Thus epiphenomenalism allows us to escape a difficult problem without succumbing to reductionism. Nor is this merely ad hoc since epiphenomenal facts are quite common in nature—the norm, we might say. The metaphysical picture is that nature has two layers: an underlying layer of causal machinery, which is quite restricted, and an overlying layer of epiphenomenal properties that coast on the first layer. A perfectly reasonable hypothesis is that the causal layer consists of nothing beyond the four fundamental forces identified by physics; the rest of nature is not in the causal line of business (save derivatively). It is thus quite wrong to think of nature as exclusively composed of causal facts. The four basic forces do all the causal work while the rest of nature stands by without lifting a finger.[4]

[1] Causation is all about the induction of motion, but pure geometry lies beyond this. Which geometry holds of nature need not impinge on the causal machinery of nature.

[2] Reference is causally irrelevant, notoriously. Where is the energy emitted by the reference relation? 

[3] The brain itself has various epiphenomenal properties over and above its conscious properties, so not everything about it is causally implicated in behavior—for example, its color, its taste, its precise furrowing, and its spatial location. If the brain qua brain has epiphenomenal properties with respect to the causation of behavior, then surely the mind can. Among the epiphenomenal properties of the brain are its mental properties.

[4] This means that if you were to remove the four forces from nature leaving everything else intact all causation would be expunged. This seems like a plausible result—even the basic atomic entities are nothing causally without their accompanying forces. They are certainly not epiphenomenal.


Temporal Panpsychism

Temporal Panpsychism

In the interests of exploring every metaphysical option, I will consider the doctrine of temporal panpsychism. Several positions on time may be distinguished: materialism, idealism, functionalism, mysterianism, and panpsychism. Materialism says that time reduces to physical objects or processes: clocks, whether natural or man-made, or possibly physical processes such as entropy. Idealism says that time reduces to experiences of time—human consciousness, basically. Functionalism says that time is whatever it is that plays a certain role, notably functions as the medium for change and events. Mysterianism says that time is something whose intrinsic nature transcends our knowledge, though we know that it exists and can be measured. Panpsychism says that time has an inherently mental reality, possibly quite different from our own mental reality—a kind of free-floating river of mental being. Idealism identifies time with human consciousness of time; panpsychism identifies time with a specifically temporal form of consciousness existing independently of human consciousness (or that of any other sentient being). These positions are all analogues of positions with which we are familiar in regard to matter and space; in particular, temporal panpsychism is the analogue of material and spatial panpsychism. Just as it is thought that matter has a hidden mental nature, and that space has a mental nature too, so it is contended by the temporal panpsychist that time has a hidden mental nature. That is, wherever there is time there is a certain kind of mental stuff that constitutes it. We are not normally aware of the nature of this mental stuff (but see below) yet it is real nonetheless—it is part of objective reality. And it performs two explanatory jobs: it is the foundation of mind as we and other animals experience it, and it furnishes a substantial reality to time over and above the rather sketchy conception of time we have from common sense and from physics. It is the logical analogue of the familiar forms of panpsychism as applied to matter and space.

            Temporal panpsychism can come in two strengths, pure and mixed. The pure form maintains that only time has a mental nature—not matter and space. This nature alone suffices to explain the emergence of mind in the universe, and it confers on matter and space whatever substantial being they have. The mixed form is less ambitious claiming only that time has a mental nature in addition to the mental nature of matter and space. This is the natural view to adopt: it simply extends regular matter-space panpsychism to include time, on the principle that it would be odd if the rest of nature were essentially mental but not time. The picture, then, is that matter and space enjoy their own form of mentality while time simply adds more of the same—each has the form of mentality appropriate to its nature. Perhaps time has a more flowing mental nature than matter and space, which are relatively static. The mind of matter and space is a kind of spread-out mind; the mind of time is more of a fluid mind—more like a river than a mountain. We can also distinguish a strong form and a weak form of temporal panpsychism, analogous to parallel doctrines for matter and space: the strong form says that time has an exclusivelymental nature while the weak form holds that time has both a mental nature and a non-mental nature—a kind of double-aspect theory. Pure strong temporal panpsychism thus says that the ultimate reality of the whole world consists in the mental nature of time, and only of time: everything—including matter, space, and animal consciousness—stems from the mental nature of time. This nature might be quite alien to us—we don’t know what it is like to be time—and yet it is the foundation of everything real. Clearly this is an extreme doctrine. Alternatively, the temporal panpsychist might more modestly claim only that the mental reality of time is just one reality among others; it is limited to time itself. Matter and space have their own independent forms of mentality. A psychic trinity prevails in the universe.

            It might be wondered how heterogeneous the mental reality of time is. Is time composed of a single phenomenological quality or is it made up of several? Time seems homogenous to us, so the former alternative might seem more natural—time is, as it were, a single-note affair (an eternal C-sharp perhaps). This would pose a problem for its ability to ground the full variety of animal consciousness, but a similar problem arises for material and spatial panpsychism—they too appear more homogeneous than the animal minds they are supposed to explain. So temporal panpsychism is at least no worse off than the more familiar forms of the doctrine. But there is really no logical bar to recognizing greater phenomenological variety: maybe time just seems homogeneous—in its objective being it might be variously hued. Presumably a view of time closer to that of Relativity Theory will render such a conception of time attractive: there are many distinct times (many simultaneities), each relative to a reference frame; and time and motion are more tightly connected than we tend to suppose (plus light seems to have something to do with time). Certainly, if we link time to measuring devices, we will be able to obtain a more variegated view of its nature. If we believe that the ultimate physical reality is something called space-time–a kind of amalgam of time, space, and matter–then we can suppose that time has a richer and more complex structure than under an austerely Newtonian conception. In any case, various metaphysical options are open to us ranging from the monotonously homogeneous to the strikingly heterogeneous.

            But is there anything to be said in favor of the doctrine? Yes, in as much as other panpsychist doctrines can claim to have rational support. First, physics tells us little about the nature of time, beyond mathematically describing its structure; the panpsychist can remedy that lacuna by suggesting that time has a hidden mental nature. He can tell us what time intrinsically is—not just specify its abstract form. Russell had the idea that the intrinsic nature of matter is revealed to us in acts of introspection; we could make the same claim about introspection and time. In effect, the brain acts as a window onto the intrinsic nature of time, which is otherwise concealed from us. This nature shows up as our own consciousness of time. Second, consciousness has an essentially temporal character, as has been frequently observed: time and consciousness are closely bound up with each other. This is why some philosophers have been attracted to an account of time as essentially a psychological phenomenon. The temporal dimension of consciousness is as evident as its intentionality and its subjective character (hence time has always been central to the phenomenologists). All conscious experience is consciousness of time; there is no timeless consciousness. Thus we need, in our account of consciousness, an explanation of its temporality—and here temporal panpsychism scores well. The nature of subjective time emerges from the nature of time itself, since objective time already harbors a primitive form of temporal consciousness. The consciousness embedded in time is itself a temporal consciousness, so this is available to provide a foundation for temporal consciousness in sentient beings. The logic here is exactly the same as the logic employed by other proponents of panpsychism—we find the basis of animal minds in the primitive types of mentality generally embedded in the world. Time features in our conscious minds in virtue of temporal mentality in time itself. So temporal panpsychism has the same credentials as material panpsychism. Furthermore, it is difficult to see how it could fail to be entailed by material panpsychism, given that the very existence of physical events and processes requires the participation of time. There is no such thing as matter without time, because material things are subjects of change, so their mental reality must enable them to participate in events and processes—but then it must include time. If matter is ultimately mental, and matter changes, then time must make this possible—and how does it do that without itself having a mental nature? If we think of time as having a mental nature of the type Will, as in Schopenhauer’s philosophy, then this is what is necessary in order to get matter activated—otherwise it is stuck. The mental nature of time is what enables the mental nature of matter to undergo change.[1] Time is the will of matter’s mind. Once we go panpsychist about matter, temporal panpsychism cannot be far behind. The different types of panpsychism thus conspire together to give us the world we experience.[2]

            Are there any good objections to panpsychism, temporal or other? Of course there are—plenty of them. I have only suggested that temporal panpsychism needs to be added to the usual kinds in order to round out the metaphysical picture. We need a General Theory of panpsychism, talking in time as well as matter and space. Father Time should be granted his full measure of mentality if other parts of nature are to receive that (possibly dubious) largesse.[3]C

[1] I am not saying this is not obscure, but then everything is obscure in this area.

[2] One possible view is that matter embeds only unconscious mental states—pre-conscious qualia—and that it is the mental nature of time that converts this into full conscious awareness. Time acts as a kind of switch turning on the light of consciousness; it does so by adding its own mental nature to the (unconscious) mental nature of matter. The mental nature of time triggers consciousness in the otherwise unconscious mental states already present in matter. For example, matter supplies a subliminal perception of red (possibly in some more primordial form) and then time adds to that the secret sauce of consciousness, thus producing a conscious percept of red. That is, time is specially designed to generate consciousness as such, leaving matter to do the grunt work of producing the raw psychological materials. I have no idea if this hypothesis is true (or even meaningful), but at least it suggests a way of thinking with some theoretical structure. It has the consequence that the whole world is brimming with consciousness as a joint result of the exertions of matter in producing pre-conscious mentality plus the ability of time to inject consciousness into this basic psychological material. There is a kind of division of labor between matter and time in the generation of conscious mentality.

[3] This paper arose out of an email exchange between Rebecca Goldstein and me, but I blame myself for its existence.


Dualism Naturalized

Dualism Naturalized

Traditional dualism is characterized by two theses: (a) the mind is a separate substance (object, entity) from the brain, and (b) the mind is immaterial. These are logically independent; in particular, (a) does not entail (b). The mind could be a separate physical substance from the brain, existing alongside it. Or neither could be physical, since the concept of the “physical” is irredeemably ill defined, ever since mechanism was abandoned in the wake of Newton’s introduction of action-at-a-distance. Descartes believed both (a) and (b), holding that matter is defined by extension and mind by thought (which is not extended). But if we give up on that way of defining the difference between mind and body, we can assert that the mind is not identical with the brain (or body generally) and yet is not immaterial. Neither is the brain “physical” in any useful sense, since it harbors powers and forces not recognized by traditional materialist science (electromagnetism, notably).[1] According to modern physics, the brain consists of fields and quantum states not hard little lumps of impenetrable matter. In any case, we are under no logical obligation to describe the brain as physical and the mind as non-physical, as if this reported anything of serious significance. The brain is a biological organ, to be sure, but so is the mind—whether identical to the brain or not. So it is logically open to us to maintain that the brain and the mind are separate things—separate biological organs—without getting caught up in the matter of immateriality. The important question is not whether one is “material” and the other “immaterial” but whether they are the same or not. That is the question of dualism (versus monism) not the question of whether the world contains any immaterial substances as well as material ones. This latter question we can happily discard as antiquated, while the former question can legitimately command our attention. If the mind is indeed a separate substance from the brain, it is available as the subject of psychological predications; it is not the brain that is the bearer of mental states but the mind. Or the self, if we prefer to speak that way: the self is the thing that thinks and feels, senses and acts. According to dualism, the self exists as a separate entity from the brain, i.e. the two are not numerically identical (this is compatible with certain kinds of dependence). We can say this without buying into some supposed dichotomy of the material and the immaterial: we can be dualists without being immaterialists. We just decline to talk in that style or, if we are wedded to it, we describe the mind as another sort of physical thing—rather as earlier physicists agreed to describe electromagnetism as physical even though it was of a different nature from what had hitherto been rated “physical”. The better question is whether there are minds or selves distinct from bodies and brains: are we composed of two sorts of thing or one?

            And there are good reasons to return the answer two. For minds and selves are not individuated as bodies and brains are, as many thought experiments from the theory of personal identity show. Brains and minds have different identity conditions and don’t necessarily track each other over time or at a time: the brain can remain in existence while the mind perishes; a single mind can conceivably occupy different brains (by uploading or gradual replacement of parts); a person can survive the removal of half of his brain while brain itself is no longer fully intact; and so on. Brain and mind have different criteria of identity. The right thing to say here is that just as there are emergent properties so there are emergent objects: selves or minds are biologically emergent objects, stemming from brains no doubt, but not reducible to them. We need a robust ontology of such entities (get your quantifiers ready!) as well as the ontology of bodies and brains.[2] If we ask what the nature of these extra entities is, we have a number of options: we can stick to appearances and declare their nature to be nothing other than what is supplied by our ordinary talk of the mental, or we can postulate a hidden nature the terms of which currently escape us. The latter alternative allows us to suppose that the second substance has a real essence (as Locke would say) that could in principle be discovered and investigated, analogous to the chemical structure of familiar substances. Maybe cognitive science is even now mapping this hidden terrain. In either case we need not be silent on the question of nature: the mind or self has a nature proper to it just as the brain and body do. It is just that these natures are different. Of course, there is interaction between the two, and a dependence of mind on brain, and an interlocking of function—but not numerical identity.[3] The case is like the distinction between lungs and heart: not the same things but plenty of interplay.

            To what extent do these separate entities share attributes? Here is one notable overlap: both are temporal. Brain processes take place in time, and so do mental processes. Both things are temporally extended (unlike abstract entities such as numbers). Descartes never denied that, merely insisting that the mind is not spatiallyextended. This is actually quite a concession, because it locates both mind and body in the same world of changing perishable phenomena—in nature, in one sense of that pliable term. And then there is the possibility that the temporal must have a foot in the spatial, if time and space have any necessary connection. In any case, the mind shares with the brain the attribute of temporal existence. What about spatial extension itself? The question is not straightforward: admittedly, the mind does not belong to phenomenal space—we don’t see it as thus extended—but it might nevertheless belong to noumenal space, whose nature may be capacious enough to include it. Maybe the mind is extended in this possibly unimaginable space—it takes up some of it. Certainly it exists cheek by jowl with spatially extended matter, so one might suppose that it cannot be quite removed from space; conceivably the two join together in a type of space that defies our ordinary conceptions. So, pace Descartes, we might allow that thought has a spatial aspect, even though we have no perception or conception of it. Actually I think this idea has a good deal to be said for it, but I won’t go into that now; it is enough to remark that the two substances could resemble each other in point of space and time while still being genuinely distinct. This would be quite different from classic forms of metaphysical dualism.

            Surely this picture fits the case of animals better than the religiously tainted picture in which the immortality of the soul must be guaranteed. The mind of an octopus, say, which is remarkably rich, is not identical to its widely distributed brain, but it can hardly be deemed “immaterial” in the sense that it could exist without the octopus’s body and brain. Its mind is an adaptive organ, evolved from more primitive attributes, and not to be identified with its brain (ditto the octopus self)– yet the metaphysics of the immaterial substance hardly fits the case, or the immortality of the octopus soul (sadly). We can allow ourselves to speak of these things as distinct from the octopus’s body without incurring the charge of immaterialism. Dualism is alive and well but it is no longer in cahoots with immaterialism. There is nothing “unnatural” about accepting that the mind is an entity distinct from the brain—that is, a type of substance dualism. And there is nothing supernatural either—nothing evidencing divinity. Given that we already accept a dualism of properties, this is indeed the natural way to go: we need a suitable object to go with these properties, to be their proper subject. There was always something funny about ascribing mental properties to brains and their parts for fear of raising the specter of the immaterial soul.[4]            

[1] I won’t go into the full rationale for saying this here; it has been well documented elsewhere (Chomsky et al). 

[2] The metaphysical background to what I am saying here is supplied by all those puzzles of identity we are familiar with: the statue and the piece of bronze, organisms and the matter that composes them, objects and the property bundles that characterize them, etc. Leibniz’s law does the heavy lifting in distinguishing objects we might lazily have supposed identical.  

[3] You might try to respond by conceding the non-identity of mind and brain but contend that the former is constituted by the latter, thus preserving the spirit of materialism. The case is like the relation between a statue and the lump of matter that composes it: not identity, since they have different persistence conditions, but constitution—there is nothing more to the statue than the stuff that composes it. But this analogy fails, because it is not that the mind simply has to assume a certain shape to be what is: the mind isn’t the brain in a certain geometrical form. If there is a constitution relation here, it is nothing like the familiar paradigms. Similarly, we can’t model the mind-brain relation on, say, the relation between water and its constituent molecules: the mind is not a collection of physical constituents, viz. neurons. So the dualism is far more pronounced than these alleged models would suggest, and hence identifying the mind with the brain is a far more problematic position. In fact, we really have no idea how to understand this relation; we only know that the mind is a thing distinct from the brain, in both the identity and constitution senses. But the general nature of the link between mind and brain appears sui generis.

[4] There are those who proudly describe themselves as property dualists but wouldn’t be caught dead defending substance dualism. This paper is intended to allay their qualms by making some necessary distinctions. The main point is that mere ontological dualism has no immaterialist implications: all that follows is that the mind is not a congeries of neurons (with only the properties ascribed to neurons in current neuroscience). 


A Puzzle About Knowledge

A Puzzle About Knowledge

I want to discuss one of the oldest problems in philosophy, not aiming to solve it but with a view to articulating its difficulty. It has a claim to shaping the entire history of Western philosophy, refusing to go away. I mean the problem of a priori knowledge or, as we are apt to say, knowledge by means of pure reason. It is not generally supposed that a posteriori knowledge presents the same problem, though it may present parallel problems. It is supposed that we know about particulars by perceiving them: we have a faculty of perception and it enables us to acquire information about particular things located in space and time. It is not thought impossible to gain such knowledge (putting skepticism aside), because perception makes it possible. It is often maintained that perception works causally, so that perceptual knowledge is simply an effect of external particulars operating on us. This is no doubt oversimplified and not very explanatory, but at least we have a sketch of how empirical knowledge is possible. A further assumption is that we can’t gain knowledge of particulars except by perception (this is the core of empiricism)—in particular, pure reason cannot provide knowledge of particulars. That certainly seems true, but its truth is not as transparent as one might wish. Why is it that reason cannot supply us with knowledge of particulars, if it can supply us with other types of knowledge? Why are we limited to our senses in gaining knowledge of particulars—what is it about particulars that demands such a route to knowledge? Couldn’t we have innate knowledge of particulars, though we have none as things actually stand? Couldn’t we be suddenly blessed with a more direct way of finding out about them? These questions are reasonable enough, but the possibilities they envisage seem remote to the point of non-existence: we must know about particulars by perception and not by our rational faculty alone. Why that is remains obscure, but it does seem that particulars are necessarily known by perceptual means. Just as it is thought that we can’t know about abstract objects except by means of our reason, so it is thought that we can’t know about concrete objects except by means of our senses. In any case, that is not the question I wish to discuss, which is the nature and possibility of a priori knowledge: what kind of knowledge is this, what is its origin, and is it really possible?

            We can take Plato’s treatment of Socrates and the slave boy in the Meno as our paradigm example: the boy is brought by judicious questioning from Socrates to discover Pythagoras’ theorem. On the face of it he relies on his own inner resources in coming to have this knowledge—he doesn’t perceive a whole lot of triangles and then infers the truth of the theorem. So it appears that his gaze is directed inward—at his concepts perhaps. His concepts guide him to the truth not his senses. Does he perceive these concepts with a special inward-directed sense? No, but he has access to them somehow: his knowledge of his concepts leads him to knowledge of the properties of triangles, which are not concepts. So we might suggest that a priori knowledge derives from concepts: we move from truths about concepts to truths about the things they are concepts of. This is by now a very familiar line of thought, but it raises a tricky question: must the conceptual knowledge be gained by looking inwards or can we obtain it by examining someone else’s concepts? What if the slave boy could perceive Socrates’ concepts, or know about them by empirical inference—could he use this as a basis for knowledge of Pythagoras’ theorem? The suggestion does not seem absurd, though admittedly farfetched: surely we could in principle know about the content of another person’s concepts and use this knowledge to infer analytic truths concerning those concepts. This would not be so different from using Socrates’ verbal testimony in order to come to know the theorem—the slave boy could have just been told outright what the theorem is, thereby coming to know it. So is it that such knowledge can be obtained by looking outwards, though it is generally not so obtained? But here an interesting point arises: if the boy had come to know the theorem this way, his knowledge would have been quite different from what it is when he comes to see it for himself. We want to say that he really knows it in the latter case, but only takes it on trust in the former case. He understands it, grasps it, and has insight into its truth. So it is the wayhe knows it that makes the difference—by consulting his own concepts. And doing so in that special way we use when engaged in a priori inquiry (not by looking at our own brain, say). The knowledge has a special meaning for the boy: it strikes him in a certain way. So what is this way—what kind of knowledge is it exactly? When we know something a priori what precisely is our state of mind—what specific type of knowledge do we possess?

            Here Plato came up with a brilliant idea: it is a form of memory knowledge. This is his recollection theory of a priori knowledge—the doctrine of anamnesis. There is nothing like remembering an earlier experience for searing it into your mind—say, what you were thinking and feeling on a certain day 10 years ago (see M. Proust). Compare this with forgetting what happened and being told about it by someone else: you might well come to know the past by means of such testimony, but it is nothing like remembering it yourself “from the inside”. You really know it then, and it would be dreadful if all your memories were erased and replaced by current testimony from other people. Memory knowledge has a special force and vivacity. Thus when Plato says that the slave boy is recollecting what he knew in a previous life he is attributing to the boy a special kind of knowledge that is not at all like hearing it from Socrates right now. We might call this the memory knowledge theory of a priori knowledge: all such knowledge is a kind of memory knowledge—though not of events in this life, but events in a previous life. Problem solved! A posteriori knowledge is newly acquired knowledge courtesy of the senses, while a priori knowledge consists of recollections of knowledge gained in a previous life. We know what recollection is, and recollection is what enables us to have a priori knowledge. There is only one slight snag: we have to believe in a previous life during which we originally acquired the knowledge in question. We have to believe in something like reincarnation (or an eternal disembodied soul). An enthusiast of Plato’s recollection theory might urge that we have here a proof of reincarnation, since no other theory can do justice to the nature of a priori knowledge; and we have the bonus that we can reasonably expect to be reincarnated ourselves. Still, the intellectually pusillanimous among us might balk at such an extravagant theory, wondering how a priori knowledge could have such momentous consequences. Did the slave boy really exist before he was born stuffed with mathematical and other a priori knowledge? Does he now really recollect what he knew then?

            Perhaps we can take the sting out of the theory by updating it. Isn’t genetic transmission a bit like memory? If your parents possessed an item of knowledge genetically, which they pass on to you, isn’t it as if you are recalling what they already knew? Not phenomenologically perhaps, but at least in the sense that a piece of knowledge is being recovered from the past—from a past life in which it was explicitly known. Thus instead of recollection we could postulate genetic transmission—a form of information storage that can be accessed at a later date. Not memory but the DNA. True, recovering such information doesn’t feel much like memory, but this provides a theory of the origin of the knowledge in question, given that it cannot derive from the senses. It doesn’t have the poetry of Plato’s theory, or its power to provide a unique flavor to a priori knowledge, but it does give us an origin story. Socrates was accessing the slave boy’s genes, in effect. The trouble with this theory, which it shares with the recollection theory, is that it is regressive: for how was the first piece of a priori knowledge acquired? It couldn’t be the result of genetic transmission or of recollection. At some point someone had to gain the knowledge in question ab initio—it couldn’t come from a previous life or from antecedently existing genes. So there is no real explanation of the origin of a priori knowledge—no account of how it arose in the first place. How did the slave boy in his previous life come to know Pythagoras’ theorem? Not by recollecting it from a previous life, on pain of infinite regress. How did the first human come to know the theorem? Not by genetic transmission from a previous knower of it. Both theories really leave us exactly where we were, without any account of the origin of a priori knowledge. We are left saying, “We just have it” or “It just pops into our mind”.[1]

            The problem is exacerbated by the fact that this kind of knowledge concerns things external to the mind not psychological matters. It is not like introspective knowledge. Pythagoras’ theorem is about triangles not ideas of triangles. How can we know objective facts by looking inside ourselves? How can we discover truths about objectively existing universals by consulting our inner psychological states? Thus a priori knowledge is puzzling, even paradoxical, and seemingly impossible. The theory of anamnesis, though ingenious, does nothing to resolve this puzzle, merely burying it; and the same is true of the genetic theory. And invoking universals, as in the theory of forms, just accentuates the difficulty, suggesting the existence of a perceptual relation that is false to the facts. We don’t see universals.  A priori knowledge remains a mystery–far more so than a posteriori knowledge. It is knowledge we gain by directing our attention inward, but we have no model of how it works—no explanatory framework. The same knowledge cannot be acquired in any other way, but that fact too is mysterious. The slave boy appears to perform a miraculous feat, conjuring his geometrical knowledge from nowhere, but the same feat is performed by every normal human. Even allowing for recollection of a previous life is inadequate to explain it. It seems to well up from nowhere, unlike a posteriori knowledge, which pours in from outside.[2]C

[1] Russell maintained in The Problems of Philosophy that we have “acquaintance with universals”, analogous to our perceptual acquaintance with particulars, but he gave no account of the nature of this alleged acquaintance, and it is hard to see how the analogy can be sustained (ditto for Godel’s remarks on “intuition”). Clearly we have a faculty of a priori knowledge, but how it works remains as mysterious today as it was in Plato’s time.  

[2] The desire to give reductive accounts of the a priori, such as those proposed by the positivists, is therefore perfectly understandable, if hopelessly implausible. I think Plato’s anamnesis theory is the best theory ever proposed for dealing with the problem, but it runs into insurmountable difficulties. One difficulty I don’t mention in the text is that it is curious that these memories from a previous life show no tendency to degrade and disappear, like ordinary memories. They might even persist unaltered across multiple lifetimes without ever being evoked, if there is no occasion to bring them to light. In addition, we don’t normally react to acquiring a new piece of a prioriknowledge by saying, “Oh yes, I remember that!” I should also note that a priori knowledge brings with it modal knowledge to the effect that the known proposition is a necessary truth. This introduces another layer of epistemic perplexity into the picture. Really the whole thing is utterly baffling. And let’s not forget that a priori knowledge and a posteriori knowledge interpenetrate in our cognitive lives, with the perplexities of the former bleeding into the latter (logic, for example).  


Why Materialism Collapses Into Panpsychism

Why Materialism Collapses Into Panpsychism

Weak materialism is the thesis that mental properties are aspects of entities (states, events) that also have physical properties, as with token identity theories. Strong materialism is the thesis that mental properties are physical properties, as with type identity theories. The physical properties are typically taken to be properties of the brain, specifically neurophysiological properties. It is not generally supposed that mental properties are instantiated outside the brain—so the materialism is taken to be a brain-centered materialism. The materialist doesn’t tend to think that mental properties are instantiated in the world at large simply because they are instantiated in the brain; the materialist is not a panpsychist. But it is difficult to see how materialism can avoid sliding into panpsychism because of the following question: why are brain properties so special that only they are accompanied by mental properties? What restricts the mental to the cerebral, given that the brain is just a physical object like others? If physical properties are co-instantiated with mental properties in the brain, why aren’t they also co-instantiated with them elsewhere? Shouldn’t nature be uniform in this respect? Suppose some Martian scientists, composed of exotic material unknown to us and without brains like ours, were to visit earth and investigate terrestrial brains, discovering that they house mental properties as well as physical. Wouldn’t it be a reasonable induction on their part to infer that other matter on earth must also be correlated with mental properties? After all, there is nothing special about the matter of the brain—it is just complexes of molecules—so we would expect that matter in general would show the same correlations. If mind supervenes on matter in the brain, why shouldn’t it supervene on matter in other locations? There is nothing unique about matter in the brain—that is the whole point of materialism—so matter should exemplify mind everywhere. To be more specific, if it is electrical activity in the brain that is key to the existence of mind, then electricity should be associated with mind wherever it exists—which is pretty much everywhere. Hence materialism collapses into panpsychism.

            It is true that this seems odd from a human perspective, because we don’t normally suppose that mind exists virtually everywhere—that is not our commonsense conception of the world. We feel it only in ourselves and infer it only for beings similar to us. But consider this analogy: we have discovered that heat is molecular motion, but molecular motion exists almost everywhere, so heat does too, despite that being contrary to what we normally think. Even cold objects have heat in them! Only at absolute zero—a rare state of affairs—does heat disappear. It isn’t that heat exists in boiling water but not in rainwater despite molecular motion in both—that would be contrary to the uniformity of nature—but rather that our common ways of talking are in error. The thermal and the molecular-dynamic are indissolubly connected, contrary to initial appearances (we only feel heat in certain things as a result of the peculiarities of our contingent senses). Similarly, we only feel mind in the case of brains, but since mind is an aspect of matter in brains, it is also an aspect of matter elsewhere—by the uniformity of nature. It isn’t that mind miraculously disappears from matter once matter leaves the confines of the head! That matter came from elsewhere and will go elsewhere, so it had mind in it from the beginning and will go on having it. Another analogy: suppose we discovered that liquid water is H2O but had never thought about ice being water (we have never seen the transition from solid to liquid water); then we discover that ice is also H2O. It would be wrong to declare that not all H2O is water because ice is H2O but not water; rather, we have discovered, contrary to our initial impressions, that water is more widespread than we supposed, existing also in the frozen polar-regions. In the same way the panpsychist maintains that the co-existence of mind and matter in the brain is not an isolated freak of nature; rather, it is a universal fact of nature. If matter can be mind in the brain, then it must be mind elsewhere too. Thus materialism and panpsychism necessarily go together.

            This is not a problem for materialism per se; it just turns out that materialism implies that mind is spread more widely than is commonly supposed. It turns out that it is spread as widely as electricity, this being the important physical property in the case of the brain. We already knew that mind has two locations in the human body—the brain in the skull and the enteric nervous system (the “bowel brain”).[1] Not exactly pan- perhaps, but at least bi-: so we should be prepared to accept that the mind is spread even more widely. Nor is this at all inconsistent with materialism: materialism says that the mind is in the matter of the brain; panpsychism says there is mind wherever there is matter. Everywhere that mind is matter is there too, which is the essence of materialism (either weak or strong). Nothing dualistic is implied by panpsychism. It is just that the materialist might be surprised to find himself a proponent of panpsychism—that wasn’t quite what he signed up for. But if you insist that the essence of mind is matter, don’t be surprised if mind turns up everywhere that matter is. The only way out of this is to claim that some kinds of matter are special, capable of producing mind while other matter is mentally inert; but that is to give up on the materialist doctrine—mind is not spooky matter! And don’t start waving your hands about the brain’s complex organization: that is not what the materialist is maintaining, but rather that mental properties are tied to matter as such—not its abstract organization (whatever that is exactly). As some wit once remarked, British Rail is complex and organized too, but it isn’t conscious! No, the materialist may as well acknowledge that panpsychism comes with the territory—just as pan-thermalism does.

            What does not imply panpsychism is dualism: if the mind has nothing essentially to do with the brain, then there is no argument showing that it must be found associated with other physical things—for it may exist in isolation from the matter of the brain. Mind could be annexed to other physical things, according to a dualist, and so is not inextricably connected to specific sorts of matter. Nor is it an inevitable accompaniment of matter, or matter of it. Similarly, if heat had nothing to do with molecular motion, there would be no argument showing that heat exists wherever there is molecular motion. So dualism does not imply panpsychism. Nor does a view that asserts the existence of a special mind-producing property in the brain, perhaps unknown, that is not found elsewhere.[2] So long as this property is found only in the brain, there is no slide into panpsychism, since it is not matter as such that is the determining factor. Functionalism could go either way, depending on how it is formulated: if it is just the existence of causal inputs and outputs that matters, we get a similar slide; but if we try to beef it up with something conceptually richer, the answer will depend on how widely that beefed up functional property is distributed (biological function will certainly involve a good deal of spread). If functionalism is taken as a species of materialism, then it will surely tilt in a panpsychist direction. So actually it is hard to avoid the panpsychist spread in anything short of something pretty drastically dualist, i.e. something that links mind uniquely to something far more restricted than matter (or electricity, or cellular structure, or functionality). It is not so much that materialism (and like doctrines) are too materialistic; it is more that they are too mentalistic—for they find mind spread far and wide and in the most unlikely of places. Materialism makes the whole physical world mental.

            It is a good question how widely the net of panpsychism should be cast. People often say that atoms are to be construed as having mental properties (or “proto-mental” properties blah-blah-blah), as if this demonstrated the boldness of the doctrine. But that can hardly be the logical end of the line. What about electrons and protons? What about quarks and strings? Does panpsychism apply to points in an electromagnetic field? What about points in empty space? What about the laws of nature—are they also partly mental? And what about time—do instants have a mental dimension too? Mental events and processes occur in time, so is their temporal nature a result of the mental aspect of time itself? Or is it just plain old non-mental time transposed to the mind? But then won’t it be left unexplained how psychological time can exist? The logic of panpsychism is extremely far-reaching, making everything in the world a repository of the mental. Do numbers have a mental nature too? Are geometrical shapes mentally endowed? In any case, depending on how far we push panpsychism, materialism will require us to accept some version of it. Just by identifying pain with C-fiber firing we could end up claiming that space and time are bubbling with mentality! For C-fibers are just matter in one configuration, and it’s the matter that counts not its configuration (how could that—a matter of mere geometry—be what pain consists in?).[3] If mind is associated essentially with this kind of matter, the kind in the brain, then it must be associated with all matter, on pain of denying the uniformity of nature (as well as invoking an ad hoc stipulation). Thus materialism turns out to presuppose panpsychism precisely because it seeks the basis of mind in matter. Being located in the brain does not alter the intrinsic nature of matter, so materialism is committed to the idea that matter as such is the basis of mind—and matter is everywhere. Only an arbitrary stipulation can prevent mind from cropping up wherever matter does. Fine, if you are OK with panpsychism, but not otherwise.

            Note too that the same slide occurs on a less macro scale once we remember that not all of the brain is associated with mentality. Only some neural clusters are correlated with mental states, not all, yet they all share the same basic morphology and physiology. So it can’t be physical cell-type that makes the difference. The natural response is to declare that all the neurons in the brain are at some level endowed with mental properties, or else our materialism will be unacceptably arbitrary—what we could call pan-neural-psychism. But then the question will be why stop there—why not include heart and kidney cells? We have discovered that all the cells of the body have mental properties, given that we know that some of them do. The point is that it is impossible to stop the spread of the mind once we accept a materialist view of the mind as we locally conceive it. If C-fibers suffice for pain, or necessarily have pain as an aspect, then why don’t other fibers, whether in the brain or outside it? And why does it have to be fibers and not some other physical feature? To repeat, there is nothing special about the matter of the brain, even (especially) according to the materialist, so we can’t avoid inferring that mind must be present wherever there is matter. Universal mentalism follows from local materialism (not deductively, of course, but as a matter of overall theory). That is surprising perhaps, but not necessarily disastrous. From the point of view of the panpsychist, it turns out that grounds for believing materialism are grounds for believing panpsychism: if materialism is true, then panpsychism has to be true too, on pain of an arbitrary stipulation.[4]

[1] See The Second Brain, by Michael Gershon (1998).

[2] I discuss such a view in “Can we solve the Mind-Body Problem?” (1989).

[3] It is generally accepted that it is not the color or location or size of C-fibers that matters to their being pain, so why should their shape make all the difference? It is the matter itself that is supposed to constitute the pain—but then why not pan-painism? What’s so special about neurons? They are just particularly stringy biological tissue, which itself is made of non-biological components.

[4] If the mental is the physical, then the physical is the mental, by the symmetry of identity. That is, if mental states are identical to certain physical states, then those states are identical to mental states, and hence the physical states necessarily imply the mental states (C-fibers are pain in every possible world). The point then is that there is nothing special about those physical states, so that panpsychism is the only reasonable position. They are not states with a special magical glow. 


Phenomenology of A Priori Knowledge

Phenomenology of A Priori Knowledge

What is it like to know something a priori? How is it subjectively to know (say) that nothing can both be and not be, or that 2 + 2 = 4? The traditional definition of a posteriori knowledge has it that such knowledge is “dependent on experience”, while a priori knowledge is knowledge that is not dependent on experience. But what is it to know something “by experience”? What properties of experience are relevant to determining the status of an item of knowledge as a posteriori? And how do these properties affect the phenomenology? Evidently an experience is a conscious state, so we would expect that the phenomenology of consciousness would play a role, i.e. what an experience is qua conscious state. It is a specific type of conscious state—the type associated with the operation of the senses. We might then suppose that subjectivity is important: the property of being graspable only from a specific point of view. Then we could say that a posteriori knowledge is knowledge based on evidence that can only be grasped from a specific point of view, i.e. subjective evidence. By contrast a priori knowledge is not based on such subjective evidence—perhaps it is based on objective evidence, i.e. the kind that can be grasped from any point of view. That is certainly an interesting way to formulate the distinction, though it seems rather theory-laden as a criterion of the a priori. Experience is subjective in this sense, but being so seems irrelevant to the distinction in question; and it isn’t clear how it affects the phenomenology of the two types of knowledge. Is it that a posterioriknowledge can only be grasped by someone who shares the type of experience in question, while a prioriknowledge can be grasped irrespective of sharing experience types? But how does that affect what it is like to be the subject of the two types of knowledge? How does the phenomenology differ? Alternatively, we might interpret “experience” to mean “as a result of past experience”, where we use the notion of what has been learned in the past. Then the idea will be that a posteriori knowledge is knowledge acquired by evidence gathered in the past and now stored in memory, while a priori knowledge is not so acquired—it doesn’t rely on “past experience”. This has nothing to do with subjectivity and points of view, and it is a perfectly acceptable use of the word “experience” (“I’ve had a lot experience bird watching”). But it is silent on the question of phenomenology: it says nothing about how it seems to the subject to have the two types of knowledge. Maybe it has implications for phenomenology, but it isn’t a phenomenological description. So is it that there is no phenomenological distinction here—no difference of seeming? Is it that the subject cannot tell the difference between the two sorts of knowledge by means of introspective awareness? There is no phenomenological divide between knowing something a priori and knowing something a posteriori—though there is indeed a distinction between the two types of knowledge. Does the traditional epistemic distinction have a phenomenological counterpart?  

            We do better to change tack and consider intentionality. One of the characteristics of experience is that it has intentionality—experiences have objects (not necessarily existent). When a subject acquires a piece of a posterioriknowledge she has an experience of an object, as it might be a bird she is seeing. But, it may be thought, a prioriknowledge, not being experience-based, has no such object—it is objectless. This would certainly be reflected in the phenomenology: in one case experience of an object, in the other no experience of an object, because no objectat all. Intuitively, one acquires empirical knowledge by experiencing objects, but rational knowledge does not involve experiencing any object—it comes from “pure reason”. This differentia seems to fit paradigm cases of a priori knowledge quite nicely: our logical knowledge is not based on any apprehension of objects but (as we obscurely say) arises from our grasp of concepts; and our knowledge of analytic truths comes from senses not references. There is nothing like seeing a bird involved, because there is nothing experiential that is involved—and hence no experienced object. Thus a priori knowledge is objectless knowledge, and this is a phenomenological fact about it. It has a distinctive type of intentionality—involving concepts not objects, to put it simply.[1] Alternatively, we could say that a priori knowledge is directed to universals while a posteriori knowledge is directed to particulars: abstract not concrete, general not specific. 

            But this suggestion runs into a problem with mathematical knowledge. According to Platonism, numbers are objects, so isn’t knowledge of mathematics a posteriori according to the suggestion that an intentionality of objects is necessary and sufficient to make something a case of the a posteriori? Other metaphysical theories of mathematics would not have this consequence—formalism, fictionalism, logicism, maybe intuitionism—but shouldn’t mathematics be a priori even under Platonism? Actually that is not so obvious on reflection: suppose cosmologists discover a peculiar kind of light matter in a remote section of the universe that gives off a faint kind of energy that is perceptible by the human nervous system—and this is associated with mathematical knowledge. Wouldn’t we then say that it has turned out that mathematical knowledge is a posteriori? There is a type of experience of mathematical objects, barely perceptible, that gives rise to mathematical knowledge, thus rendering it a posteriori. But there is also this question: even if there are mathematical objects, are they part of the phenomenology of mathematics? That is far from clear: does it seem to us that Platonism is true? Is that a datum of consciousness? And what notion of object is in play here? It is certainly not the notion of material particulars in space, or even mental particulars in non-space. We don’t feel ourselves confronted by numbers, as we feel confronted by physical objects—faced with them, assailed by them. To call numbers objects seems like a stretch, precisely because that is not true to the phenomenology: it doesn’t seem to us that numbers are at a certain distance from us and each other, or that there is perceptual constancy with respect to our perception of numbers, or that there is a type-token distinction for numbers. Talk of objects here feels theoretical and tendentious not natural and intuitive. Nor does anyone ever argue that Platonism must be true because numbers seem like objects. Nor is it that our mathematical knowledge is produced by anything deserving the name of experience, so we don’t have it as a result of experiences of objects. So we can reasonably say that mathematical knowledge is not object-directed from a phenomenological point of view; it is nothing like our knowledge of material things in this respect (this is why non-Platonist theories don’t immediately strike us as false to our lived experience with mathematics). It is true that mathematical knowledge is problematic—notoriously, it isn’t causally explicable—but it is not obligatory to describe it as phenomenologically object-directed. And even if it were, we could always amend our criterion to say that a priori knowledge is not based on experience of particulars—concrete spatiotemporal entities—but rather on the apprehension of abstract entities (non-particulars).

            There is a further fact about sensory experience that distinguishes the a priori from the a posteriori, namely the role of the sense organs. It is part of the phenomenology of empirical knowledge that we are aware of our sense organs, and hence our body. I know, for example, that my current experience of a bird is visual and that my eyes are involved in having such experience. When acquiring knowledge empirically I am aware that my senses are operating in a certain way—my eyes and head are moving, for instance. This is a part of the phenomenology—not just external objects of experience but also the object that is my body, specifically the physical sense organs. But in the case of a priori knowledge there is no such awareness of my body—I am not aware of a bodily sense organ responsible for picking up information about the objects of my a priori knowledge. I am not aware of a part of my body vouchsafing to me mathematical knowledge, say. Of course, the brain is involved in having such knowledge, but the brain is not a phenomenological component of acquiring that knowledge—there is no bodily sense organ geared to the mathematical world. So there is a double independence from objects: no external object of awareness, and no bodily object producing awareness. In gaining empirical knowledge I have awareness of external objects and I also have awareness of my own body as a mediator of knowledge, but neither is true of a priori knowledge. In this sense the phenomenology of a priori knowledge is disembodied as well as objectless.

            I would describe a priori knowledge as phenomenologically empty: it is not experiential or object-directed or body involving. By contrast a posteriori knowledge is full: replete with objects and the body and subjective experience. Sartre might say that the former is a phenomenology of Nothingness while the latter is a phenomenology of Being. Of course, a priori knowledge has intentional objects—concepts, universals, abstract entities—but these don’t saturate consciousness in the way the components of a posteriori knowledge do. I am now aware of my visual experience, its concrete objects, and the body that enables me to have experience of objects: but I am not likewise aware of such things when I think about logic or numbers or analytic propositions—I am simply aware of certain truths. I am aware of the apparatus of knowledge in the former case, but not in the latter. Thus a priori knowledge seems more mysterious to me, because I can’t apprehend its machinery—what makes it possible. From a phenomenological point of view, it seems like a deliverance from on high—a kind of miracle. I can know that 2 + 2 = 4! How I know this, I don’t know—but I can know what makes my knowledge of my immediate environment possible, viz. experience, perceived objects, and my sense organs. This is the phenomenological upshot of the traditional way of marking the distinction between the a priori and the a posteriori: it arises from the nature of sense experience as a phenomenological category. The phenomenology of a posteriori knowledge is the phenomenology of experience as object-directed and body-mediated; the phenomenology of a priori knowledge is absent these components, presenting itself rather as objectless and disembodied. The body and the perceived world are phenomenologically irrelevant to the etiology of a priori knowledge. It appears to transcend such things.[2]

[1] Of course, both sorts of knowledge have objects—either concepts or objects—it is just that concepts are not objects. This is the familiar ambiguity of “object” as between a type of entity and being a target of a mental state (an “object of thought”). 

[2] I am not saying it does transcend the world of material particulars—we need a body and brain to have a prioriknowledge—but as a matter of phenomenology these things don’t enter the picture. Hence a priori knowledge has a curious thinness and impalpability. It is characterized by absence—what is not suffused by experience, objects, and the body.


Philosophy and Politics

Philosophy and Politics

It would be naïve to suppose that philosophy in the twentieth century was sealed off from the political turmoil of the period, particularly two World Wars followed by a Cold War. Philosophers, being intellectual people, would naturally look to the causes of war (and oppression generally) in various forms of defective thinking: ideologies, social conformity, propaganda, delusion, irrationality, and sheer nonsense. They would then set themselves to rectifying these deformities of thought, hoping thereby to prevent war and other forms of violence. They would see themselves as thought doctors and intellectual scolds. Thus religion, pseudo science, superstition, political ideologies (fascism, communism, etc.) would be subjected to philosophical scrutiny, followed by condemnation. Positivism is one extreme (and therefore attractive) form of this tendency, declaring much of traditional discourse literally meaningless: the chief cause of war is nonsense, to put it simply. This diagnosis fits religious wars and with some tweaking carries over to wars powered by ideology. Karl Popper, though not a positivist, shared the aim of cordoning off the shabbier precincts of intellectual culture—particularly, Marxism and Freudianism. Other philosophers put their faith in symbolic logic or the down to earth prescriptions of ordinary language. Philosophers felt the need to oppose forms of thinking and talking that fostered dangerous tendencies, so there was a political rationale for their activities. The search for a criterion of meaningfulness (or a demarcation criterion in the case of Popper) was at least in part prompted by political concerns—concerns about war, human welfare, and human enlightenment. It was not a purely intellectual matter. Philosophy was seen as politically useful. The same could be said of phenomenology and existentialism, notably in the shape of Heidegger and Sartre, whose writings have a clear political motivation. We need to focus on lived experience, Dasein, the for-itself and the in-itself, the indisputable facts of Being. These philosophers oppose tendencies of thought that produce social discord, alienation, and sickness unto death. Twentieth century philosophy is thus shaped by political considerations; it is not a pure inquiry cut off from “the real world”. It is, in a word, relevant.[1]

            Nor were previous centuries all that different. Without rehearsing all this we can report that philosophy was shaped a good deal by religion, that it was concerned to promote the reputation of science, that it addressed itself to issues of political authority in an age of monarchy.  Opposing or supporting the Church was a central concern of philosophy throughout the middle ages, coming to a head in the Renaissance. And, of course, there was plenty of war to fuel interest in its intellectual causes (I am speaking mainly of Europe, but elsewhere in the world much the same situation existed). Philosophy was not disinterested—disengaged from large political and social issues. Only in the time of the ancient Greeks does philosophy appear serenely removed from politics, though here too appearances may be deceptive. True, Plato and Aristotle undertake inquiries whose political relevance is at best obscure (particulars and universals, substance and form), but politics occasionally intrudes in the form of the Sophists, the nature of the ideal state, democracy, and the death of Socrates. Were Socrates’ own motives completely apolitical? He went around exposing lazy thinking, questioning traditional pieties (the Euthyphro argument), and upsetting the authorities: why would he do this unless he thought that the errors he exposed were harmful? If they were just harmless eccentricities, silly personal foibles, he might have devoted his energies to other pursuits; he clearly thought it mattered that people are so intellectually inept. It mattered to the body politic. Still, I think it is true to say that the spirit of pure inquiry was very much alive in this period of intellectual history; one doesn’t sense the philosopher looking over his shoulder at the political ramifications of his studies. Perhaps this is because the time was one of relative peace with little internal conflict and a sense of freedom. The ancient Greeks did not feel themselves to be at odds with dangerous ideologies that philosophers must be conscripted to combat (at least that is my impression). However, this period didn’t last long and philosophy took up the cudgels against foes and phonies. The philosopher conceived himself in oppositional terms—always fighting with someone, always aiming for the Greater Good. The philosopher was ipso facto a political philosopher.

            The same is not true of other disciplines. Mathematicians and physicists are not politicians: they don’t conceive their subject as primarily concerned to combat dangerous intellectual error on the part of others, or to correct shabby thinking, or to root out pernicious nonsense. Teachers of these subjects don’t announce that their purpose is to enable you to think clearly—the assumption being that clear thinking will have practical benefits. Critical thinking courses, however, are intended to foster an ability to resist propaganda and sophism of the kind offered by the unscrupulous politician. Mathematics and physics, by contrast, simply study a certain range of questions in an impartial spirit, without regard for political considerations. Wars are not caused by false physical theories or unproved mathematical conjectures! The same is true of biology, geology, history, and botany. But philosophy has always been thought of as politically relevant: philosophers are expected to have political opinions, to be politically engaged. Even within philosophy there are political battles—battles for power, prestige, funds. Analytical philosophy versus continental philosophy, history of philosophy versus timeless problems, ethics versus metaphysics: philosophers are always engaged on some sort of crusade, busily denouncing and demoting. The philosophy profession is apt to be highly politicized in one way or another. Philosophers, we are told, are concerned with how to live, and politics is about that very question on a larger scale. Nowadays philosophers are much exercised with questions of gender and racial equality, this being a new arena of political engagement for them. That is a continuation of an old tradition: the philosopher as political operative. How could it be otherwise?

            Let’s pursue that question: what would philosophy be like without political input and influence? Suppose the twentieth century had been a century of peace and tranquility: no war, no oppression, no genocide, no imperialism, no class division, no religious controversy, etc. That is, suppose the century had featured nothing of consequence in the political sphere. Do you think there would have been the same obsession with meaningfulness, demarcation principles, the hygiene of formal logic, and the bracing breeze of ordinary language? I doubt it: for none of the usual political enemies would have existed to combat. All these concerns were prompted by perceived errors that required philosophical correction—errors with “real world” consequences. Wouldn’t philosophy have looked a lot more like physics or botany? And what would that be in the case of philosophy? A concentration on philosophical problems as such—that’s what. Philosophers would simply confront the perennial problems of philosophy without regard for any political ramifications–trying to understand them, debating them, and even solving them (well, that may be expecting too much). Not that nothing of that type was occurring during the time of the politically engaged kind of philosophy (for those problems have an irresistible allure), but it was not free to go its own way without any inhibition or restraint. The subject was surrounded and infiltrated by political questions. In fact, I think that the last few decades of the twentieth century were unusually free of political preoccupations and that philosophy benefited hugely thereby. There wasn’t much need for political engagement on the part of philosophers, so they could (to some degree) pursue questions that are politically irrelevant. They rediscovered the joys of pure inquiry: they could, for example, indulge in metaphysics without fearing that they were abetting stultifying religion or war-inciting ideological nonsense. That is, the psychology of philosophers changed during this period—not completely but partially. They felt freer to pursue their vocation.[2] Imagine what it would be like if politics intruded not at all on philosophy—a type of utopia no doubt but an imaginable one. Philosophers could then focus on the problems of philosophy without having to think about anything extraneous to them. It would be like Popper without the (alleged) pseudo sciences of Marxism and Freudianism to contend with—there would be simply no need to labor over formulating a demarcation criterion. If there is no war, then we need not fret over its intellectual causes: we need not spend our time skewering bellicose ideologies with superior reasoning. We could be exclusively concerned with discovering the truth without regard to its political utility. As I say, I think some of this has been in the ascendant, but it is good to state clearly what philosophy would look like in its unadulterated form—apolitical philosophy. Politics is fine in its place, and philosophers have a role to play in improving the practice of politics, but we should not lose sight of philosophy in its ideal and primal form. It is not in its essence prophylactic or therapeutic or anti-irrational or politically progressive. It is not in the business of war prevention or bullshit detection or oppression removal. It isn’t even to be understood as a good way to think clearly about things in general (that is not its essential point). It is an attempt to come to grips with certain age-old problems—a completely non-political enterprise. And there is always a danger that philosophy aimed at political ends will be dragged down to the level of politics. In my view philosophy is intrinsically apolitical, despite its history. That is indeed a main part of its attraction. We are not trying to improve the world qua philosophers but to formulate and answer the distinctive problems of philosophy. Movements like positivism are an aberration in philosophy, not part of its central mission (and let’s not forget that the avowed aim of positivism was to destroy and suppress metaphysicians, to “cancel” them).[3] In an ideal world the philosopher would have no interest in politics at all (except as a hobby)—though political philosophy would be perfectly kosher. The ivory tower would be sealed off from the outside world.

            I fear I may be misunderstood. It is not that I am against politics, and it is not that I think philosophy has no relevance to it, and it is not that I think philosophy has been wholly political for its entire history. I am merely suggesting that the exigencies of politics have shaped and distorted philosophy, which in its essence is not a political subject. Its connection with politics is contingent. In its pure form philosophy is an apolitical attempt to come up with the truth about a certain range of (pretty abstract) problems. Anything else is a corruption of its true nature.[4]

[1] I am obviously speaking in broad generalities here; the usual caveats apply.

[2] I want to avoid mentioning names for fear of omissions and wrong inclusions, but just to convey a sense of what I am talking about let me cite the following as (relatively) apolitical philosophically: Kripke, Nagel, Fodor, Strawson, Davidson, Lewis, and others. On the political side I would mention Rorty and Scruton as explicitly political in their approach to philosophy. More ambiguous figures would be Austin, Quine, Wittgenstein, and Rawls.   

[3] Isn’t it remarkable that the obsession with meaningfulness, once so urgent, has now completely disappeared from the philosophical agenda? I conjecture that this has to do with the change of political climate since the early and middle twentieth century, particularly regarding the dominance of religion. Nor are philosophers so focused these days on the question of freedom and personal authenticity, ever since the political revolution of the 1960s rendered such concerns nugatory (at least to some degree). 

[4] What is valuable about the philosophical state of mind (the philosophical life) is that it is not a political state of mind—not obsessed with power, advantage, competition, winning and losing, popularity, and influence. It is free from such worldly concerns. Not that it is easy to achieve.