I wish to examine the distinctive nature of philosophical knowledge. I don’t want to place much emphasis on the concept of knowledge; if that is too vaunted a term, we can as well speak of opinion or hypothesis or reasoning—whatever it is we do mentally when we do the thing called philosophy. But I will speak of knowledge for convenience (and because I don’t myself think the term is too strong). So: what kind of knowledge is philosophical knowledge? Two positions have been staked out: either such knowledge is a posteriori or it is a priori. It is either knowledge “by experience” or knowledge “independently of experience”. The former position is held by those who believe that philosophy is “continuous with science”: it is empiricism with respect to philosophical knowledge, i.e. the five senses are the ultimate basis of this knowledge. The latter position is held by those who think that philosophy proceeds by conceptual analysis or is akin to mathematics (hence synthetic a priori): no sense experience is essentially involved in acquiring philosophical knowledge. But this ignores a third possibility: philosophy relies on some sort of experience but not traditional sense experience. That is, there are philosophical experiences and these play a role in producing philosophical knowledge. This position allows for a kind of extended empiricism with regard to philosophical knowledge: such knowledge is based on experience, but the experience is not of the kind associated with the five human senses. It is sui generis. But what kind of experiences are these? We may cite feelings of conceptual confusion, impressions of mystery, intellectual cramps, magical imagery, theoretical frustration, moments of exhilaration, sensations of sudden insight. Philosophy has its phenomenology, its what-it’s-likeness: there is a way that consciousness configures itself when philosophy is going on in it. So these experiences are available to play a role in generating knowledge, and hence qualify philosophy as an empirical discipline in the extended sense—like logic, mathematics, and semantics (also ethics). Thus we can accept a rationalist conception of the epistemology of philosophy while maintaining that philosophy falls under a general empiricism—rationalist empiricism. We have philosophical knowledge in virtue of having philosophical experiences—episodes of consciousness in which philosophical thought is embedded. Philosophy turns out to be a posteriori, though not in the sense usually intended, but simply because experience is epistemologically ubiquitous. Yet it is also a priori in the sense that it is prior to (independent of) body-based sense experience, i.e. the five senses. We don’t need to use our five senses in order to arrive at philosophical knowledge (it is a priori relative to those), but we do use—and must use—our experiences in a broader sense (and so is a posteriori in that respect). For we use experiential consciousness when we are employing our mind about philosophical questions. Our phenomenology shapes our cognition.
But this is somewhat thin gruel unless we can say more about the distinctive characteristics of philosophical cognition. Granted we have philosophical experiences, but how are they related to the essence of philosophy as an intellectual discipline? What is the nature of philosophy such that it produces such philosophical experiences? What exactly constitutes a philosophical experience? To answer these questions we need to say more about the general character of philosophy; then we can say that philosophical phenomenology reflects this character. We need to link phenomenology with cognitive architecture—consciousness with cognitive science. So let us try to develop a cognitive science of philosophy and see what kind of experience falls out of that. This will enable us to be more explicit about the type of experience that drives the epistemology of philosophy. We will then be able to unify the structure of philosophical cognition, the epistemological status of philosophy, and the phenomenology of philosophy. So what is that structure? What makes philosophy unlike other subjects? What specific methods does it adopt? How is it related to preexisting properties of the human mind? We may begin by noting that other academic disciplines are rooted in aspects of the mind that pre-date and anticipate their academic form; they don’t spring from nowhere, psychologically speaking. They have their origins in folk psychology. Thus physics has its roots in what is called folk physics—our primitive understanding of the physical world. Obviously we need this understanding in order to survive in a world of material bodies subject to the laws of physics; and there is every reason to believe that it has a substantial innate component. It would be possible to spell out the basic operating features of the innately based folk-physics mental module (compare the innate language capacity). The general point is that academic physics has its counterpart in a preexisting psychological capacity with a specific structure and application to the real world. No doubt this capacity arose for good evolutionary reasons (organisms that are bad at folk physics don’t stick around for long). Geography clearly grows from a basic competence in mapping the surroundings of the organism: where things are, how to get from A to B, what kinds of environmental features to look out for. We used to have local mental maps (like other animals), now we have maps of the entire planet. History is made possible by memory, by an ability to keep track of the past—vital in an organism that needs to learn from the past. Primitive people told stories about what happened in days of yore (or yesterday) and academic history exploits this basic ability to construct its sweeping narratives. Chemistry is a little more obscure as to origins, but a primitive understanding of chemical reactions could prove useful in practical activities—how metals rust, water dissolves, acid burns. Perhaps cooking encouraged chemical knowledge by drawing attention to the way heat changes the form of substances. Psychology obviously develops from folk psychology, useful in a social species, and also innately based. Astronomy has its origins in our perception of the night sky and our observations of the sun and moon, which are also useful things to know about. Economics grows from primeval bartering. Political science arises from the need for government in a social species. Linguistics builds upon basic linguistic competence, a central feature of the human animal. Biology is anticipated by our ancient awareness of species, reproduction, predation, etc. Even anthropology, apparently about people from remote locations, can be seen as having seeds in our need to understand strangers, even if only from the neighboring tribe. That is, each academic discipline has roots in preexisting mental competences that serve broadly biological purposes, and it reflects those competences. A cognitive science of these basic mental capacities clearly carries over to the more sophisticated edifices that make up a modern university. The historian, say, is using the same basic capacities used by his ancestors in reconstructing the past—memory, traces left by the past, and narrative talent. Generally speaking, academic disciplines have precursors in human psychological nature, which typically serve biological functions. They thus have a certain kind of evolutionary history, or pre-history.
But what about philosophy—where is its primeval precursor? From what biological adaptation did it intelligibly spring? Here we seem to draw a blank: philosophy looks distinctly de trop, biologically pointless, lacking in identifiable function. Did it just spring from nowhere? Does it lack a natural history comparable to those just indicated? Is it humanly unnatural? I think the answer is that it stems from what psychologists call meta-cognition—the ability to think about thinking. In philosophy we reflect on thoughts, concepts, theories, arguments, inferences, reasoning: we engage in a second-order cognitive activity. And we do so in an evaluative mode: we assess validity, plausibility, coherence, cogency, etc. That is the basic structure of philosophical cognition—evaluative meta-cognition. Philosophical competence is largely meta-cognitive competence. But why do we have this kind of competence? The answer, I suggest, is that criticism came to be a useful trait in a social species—the ability to evaluate other people’s beliefs and assertions. Our ancestors used meta-cognition in their critical behavior the better to aid the group, or to establish primacy within it. A gene for criticism evolved by the usual mechanisms. The criticism might concern hunting strategies or agricultural methods or personal conduct; in any case it led to an ability to evaluate chains of reasoning and accept or reject the claims of others. Being a good critic conferred reproductive advantage—the same old evolutionary story. Language will have played a part in this because it enabled critics to express their criticisms: disputes could be aired, conclusions reached, plans adopted. All this required meta-cognition and logical competence. Self-criticism came along with it—not as a form of humility but rather as a way to prepare oneself for effective rebuttal in case of challenge. Dialectical skill had social value. So philosophy as an academic discipline has its early roots (partially at least) in the critical practices of meta-cognitive creatures. Socrates is a prime example: energetically arguing in the marketplace with overconfident conspecifics. Socrates is a born critic, a logical evaluator, a meta-cognitive savant. The dialogue form thus perfectly reflects the origins of the philosophical mind. In the course of evolving and refining this trait certain problems were discovered and grouped together—forming the subject we now call “philosophy”. So philosophy does have a quotidian source or precursor just like the other disciplines, though of a special sort. The sophists and the skeptics are natural descendants of the aboriginal arguers and persuaders of primitive human groups. Immanuel Kant no doubt had an ancestor particularly adept at tribal-gathering argy-bargy. The more meta-cognitively able you are the better (Wittgenstein was nothing if not meta-cognitive). Philosophy thus arises in a social context employing a certain cognitive toolbox: that is its cognitive science. A solitary life does not naturally lead to it; nor will a life of cognitive complacency (ants have more aptitude for it than eagles, and it will not arise in the socially uncompetitive). Perhaps our primate cousins have an inkling of philosophy, being somewhat meta-cognitive themselves. It is hard to see how far one can go in it without a language, because that is the primary means of social persuasion—though language is not by itself sufficient to kick-start philosophy. It is language used critically that contains the magic ingredient. Philosophy begins with verbal confrontation.
We can now return to the phenomenology of philosophy. Given that evaluative meta-cognition has been identified as the psychological deep structure of philosophy, it will follow that the experience of doing philosophy will embody this structure. Philosophy has a meta-cognitive evaluative phenomenology. It seems to us that certain propositions are consistent with other propositions; that some propositions follow from others; that a particular concept has such and such necessary and sufficient conditions (or otherwise); that a particular theory has a lot to be said for it; and so on. These appearances play a role in shaping our philosophical beliefs and producing philosophical knowledge. So this is the specific type of the philosophical experience—evaluative meta-cognitive experience. The philosophical experience thus resembles the logical experience, not surprisingly. Feelings of necessity and contingency are central to both philosophical and logical knowledge. Accordingly, philosophical knowledge is a species of empirical knowledge in the extended sense (but not in the traditional sense). Rationalist empiricism applies to it. Its cognitive architecture, phenomenology, and epistemology fit tightly together: cognitive architecture generates experiential phenomenology and experiential phenomenology generates knowledge. It is the same with philosophy as with other subjects.
 If science begins with wonder at the natural world, then philosophy (in the modern sense) begins with wonder at other people’s stupidity—at their ratiocinative failings. The heart of philosophy lies in the pronouncement: “That doesn’t follow”.
 The degree to which various cognitive competences are modular is up for debate. It is generally supposed that physical competence, psychological competence, and moral competence are separate modules. If so, we can predict a variety of phenomenological styles to be associated with them. In the case of philosophy, its meta-cognitive structure will align it with competences also aptly seen as meta-cognitive, such as regular introspective knowledge. The feeling of pain has a specific experiential quality, but so does knowledge of feeling pain; and this knowledge will resemble philosophical knowledge in so far as both are second order. If there were a distinctive meta-cognitive quale, it would be shared by all meta-cognitive activities. I suspect that philosophical competence is, or rests upon, a separable mental module, which is why it is not necessarily correlated with other kinds of intellectual competence. Are there any philosophical idiot savants?