Intentionality and Space
Here is a famous passage from Brentano’s Psychology from an Empirical Standpoint (1874): “Every mental phenomenon is characterized by what the Scholastics of the Middle Ages called the intentional (or mental) inexistence of an object, and what we might call, though not wholly unambiguously, reference to a content, direction toward an object (which is not to be understood here as meaning a thing), or immanent objectivity. Every mental phenomenon includes something as object within itself, although they do not all do so in the same way. In presentation something is presented, in judgment something is affirmed or denied, in love loved, in hate hated, in desire desired and so on.” (92-93) There is not a little obscurity here and many readers have fastened onto the last sentence as something clear to hang onto. But if we are to understand Brentano’s thesis we need to scrutinize the explanatory phrases with which he introduces the idea of intentionality. First “intentional (mental) inexistence”: this is not to be taken to mean “intentional (mental) non-existence”—it isn’t the idea that intentional objects don’t exist. It is the idea that they exist (reside) in the mental phenomenon: they are contained in it, are a constituent of it. Brentano alternates between “inexistence” and “in-existence” without explaining why (and neither do the translators comment on it), but the latter expression better captures what is intended, namely existence-in—what is also called immanent existence (immanent in the mental phenomenon). Next we read that this trait could also be called “reference to a content”, which introduces two new notions: reference and content. The first word suggests language and speakers, which cannot be what is literally intended, since it is not supposed that all intentionality springs from language: the mind isn’t linguistically referring when it contains an object (not according to Brentano anyway). The second word suggests some sort of conceptual representation, analogous perhaps to Frege’s notion of sense; but that can’t be right because the intentional object is more like a reference than a sense—an object not a concept. And Brentano later dropped this formulation, no doubt for the reason just stated: of course the content of a mental phenomenon is immanent in it; what is being claimed, more controversially, is that the object is immanent too. Immediately following we have the phrase “direction toward an object”, as if this were a mere paraphrase of the previous expression, which it clearly is not. The phrase “direction toward” is presumably a metaphor (but see below), and has been latched onto in subsequent writing; and the notion of object is clearly meant to connote the target (another metaphor) of a mental state—what it is about. Hence an object in this sense is not a “thing”, by which is presumably meant a denizen of the mind-independent world (a plant, an animal, a rock). Here “object” is used as it is in “object of thought”, i.e. entity thought about. We are then faced with the daunting phrase “immanent objectivity”, which could use a little unpacking (to put it mildly). The thought is that a mental phenomenon immanently (intrinsically) contains object-directedness—it is object-oriented, object-specifying. There is something object-like lurking inside the mental state. Immanence here contrasts with transcendence, i.e. existence beyond the mental state: the intentional object is not extrinsic to the mental state but right there inside it. As to “objectivity”, this is not intended to suggest real existence outside the mind, but rather the object-positing activity of the mind (Brentano doesn’t use the word “posit” in this connection, unlike his descendant Sartre). The object of a mental act is what is presented to the subject in consciousness (“presentation” is taken by Brentano to be a universal feature of the mind). Interestingly, in a footnote to the later “Attempts to Classify Mental Phenomena” (p.189) Brentano tells us that he had considered using “objectivity” to characterize the feature he wishes to identify instead of “intentionality”, because the latter misleadingly suggests the ordinary notion of intention; but then he reflected that “objectivity” would be equally misleading, suggesting to modern readers the idea of “what really exists as opposed to ‘mere subjective appearances’”. He notes that we have no ordinary-language word for the universal and salient feature of mental object-directedness, itself a peculiar fact, and that no technical term is free of difficulties. One might suggest that a neologism like “objecticity” or “objectality” might serve the purpose, but these too court misunderstanding; we may as well settle for “intentionality” despite its misleading connotations. Anyway the phrase “immanent objectivity” should be taken to mean the same as “immanent intentionality” in Brentano’s mouth: the object intended (sic) is in the mental state not outside it (not transcendent). As he says: “Every mental phenomenon includes something as object within itself”.
Readers have tended to focus on the object-positing aspect of Brentano’s notion of intentionality, and indeed it is striking and plausible, neglecting the thornier concept of intentional in-existence, i.e. object-immanence. This has enabled later theorists to avoid what looks like a tension in the notion, indeed a contradiction. For how can we reconcile the following two theses: (a) the mind is always directed toward an object distinct from itself, and (b) the objects of mental activity are always within the mind? How can the intentional object be both outside and inside the mind at the same time? How can it be both transcendent (not identical to the mental act that posits it) and yet also immanent (strictly within the mind)? Perhaps this difficulty explains Brentano’s early equation of object and content: the content is clearly immanent, which satisfies one aspect of the intentionality doctrine, but then we lose the idea of separateness from the mental act itself. Compare qualia: they are clearly immanent (on most ways of construing them), but they are not distinct from the mental state that harbors them. On the other hand, the external physical objects of perception are clearly distinct from perceptual experiences, but they are scarcely immanent in such experiences. The intentional object is called upon to be a bit of both—part immanent and part transcendent: hence Brentano’s equivocation. And yet the underlying notion seems entirely correct: if I am hallucinating pink rats, say, these perceptual objects serve to individuate my experience, and yet they are not the same as my experience (it isn’t pink and ratty). The question is how to characterize this fact accurately. I don’t think Brentano ever succeeds in doing this despite the basic correctness of his theory. He has hold of a datum but he doesn’t have a clear and coherent characterization of it. You might try saying that the object is part of the experience (not identical to it), but this too is obviously wrong—no part of my hallucinatory experience is a pink rat either. The identity of my experience is fixed by its objects but it is not identical to its objects—hence immanence combined with transcendence. There are ways to go here but they require a closer examination of the nature of intentional objects—are they perhaps combinations of universals?—but the task is not an easy one. In any case, Brentano’s introduction of the concept of intentionality stands in need of further work, sound as it may be in fundamentals. What I have wanted to bring out is the tension inherent in his formulation of the notion, which is revealed when we press hard on key phrases, particularly “immanent objectivity”.
With these clarifications in place I now want to focus on a different (but related) question: the role of space in constituting the structure of intentionality. In the most basic case the distinctness of the intentional object (hereafter the Object) consists in separation in space, i.e. perceived separation. We see the object as spatially removed from us, and hence distinct. The Object is phenomenally distant (even if it doesn’t in point of fact exist). Perceptual presentation is presentation in space. Even bodily sensations are spatially presented: the pain located in the foot, the tickle under the arms. So the Object is not presented naked, as it were, but as embedded in a spatial matrix. Even thoughts are positioned in relation to the body, roughly in the vicinity of the head. Space is the form of our sensibility, as Kant would put it. It is notable that Brentano’s most explanatory phrase, and the one that is most often repeated, uses a spatial concept—that of direction. We do indeed experience Objects as existing in a certain direction, and we direct our attention to certain portions of space. It is the same with the notion of pointing, also natural in this connection (but not used by Brentano): one points in space. The separateness of the Object is typically (paradigmatically) a spatial separation: we experience things as spatially distinct from us. We might even suppose that phenomenal space is a precondition of intentionality; it is certainly ubiquitous. Then the following thought comes to mind: the mental and the physical are not quite so different from each other as we might have supposed. For if the essence of the physical is extension, then the essence of the mental is phenomenal extension. Material objects stand in spatial relations and are extended in space; mental phenomena are intentionally directed to Objects in (phenomenal) space. Space thus enters in two ways into the constitution of reality: as the condition of material existence and as the condition of mental existence–the former by way of actual physical space, the latter by way of perceived phenomenal space. Things in actual space are not intentional in virtue of properties of extension; things not extended in actual space nevertheless incorporate space into their intentionality. The material world is extended but not directed toward extension, while the mental world is directed toward extension but not extended. So the mental and the physical are not quite so sharply distinguished as Brentano’s criterion would suggest, once we take account of the role of space in constituting intentionality. An idealist about space might suppose that actual physical space derives from phenomenal space; a realist about space might suppose that phenomenal space results from actual physical space by some sort of abstraction or by dint of outright externalism about mental representation. But even if we recognize two irreducible sorts of space, it turns out that space is the common factor between extended matter and non-extended intentional mind. There may indeed be two fundamental sorts of reality, extensional and intentional, but they are united under the umbrella of space: one existing in space, the other having space existing in it. Space (as Object) is immanent in the mind, as well as being distinct from mind, and it is also immanent in matter (but not as Object). There is a dualism of spaces here that goes along with the dualism of the extensional and intentional. Brentano talks as if the structure of intentionality exists independently of spatial representation, so that mind and matter are conceptually and ontologically remote from each other; but once we recognize that space is integral to both we see that the two are not so widely separated. To put it differently, the mind is as reliant on extension as matter is in order to have being, despite the different ways in which extension enters the picture (de re and de dicto, as it were). And it is extension that grounds the “objectivity” of intentionality, because the mind is “directed” to things in phenomenal space: the intended Object is located in space relative to the subject. I see pink rats as over there, at a certain distance from me, and this is what my apprehension of this Object as distinct (transcendent) is grounded upon. The immanence consists in the fact that this remote Object also individuates my mental state—the remote fixes the proximate. Without perceived space it would be hard to see what the distinctness of the Object could consist in, so Brentano is tacitly relying on it to ground intuitions about the intentional structure of the mental. But then he is invoking a type of fact that applies also to the physical world, only non-intentionally. It is true that there might be peripheral cases in which matter is not extended and mind is not embroiled in the spatial, but surely the central cases both involve extension in their respective fashions. Descartes taught us that the essence of matter is extension; Kant taught us that the essence of sensibility involves “intuitions” of space; Brentano taught us that the essence of mind is intentionality: put these all together and we get the result that matter is constituted by real extension and mind is constituted by phenomenal extension. Mind is directedness toward a spatially extended world, and matter is that world (granted that it exists). Physics is the study of the actually extended world; psychology is the study of mental phenomena about the (phenomenal) extended world. Mental phenomena are essentially intentional; the intentional is spatially saturated; so psychology is about mental reference to a spatial world. It is about aboutness, and aboutness is spatially constituted. The laws of psychology therefore concern spatially imbued intentional states (e.g. the laws of psychophysics). We can abstract away from phenomenal extension in psychology, as we can abstract away from actual extension in physics, but the subject matter is inextricably bound up with extension in both cases. In particular, the mind is inherently intentional in Brentano’s sense (suitably cleaned up) and up to its neck in spatial representation. So there is a kind of metaphysical unity at work here despite the deep ontological differences between the mental and the physical.
 It might be thought that mathematical intentionality is a counterexample to the claim of spatial universality, since we don’t apprehend numbers as existing in space. Mathematics is a special case in many ways, and its ontology is highly debatable, but I would note the following point: we do apprehend numbers as public objects in the sense that the same number can be grasped by many minds (unlike particular states of mind). This is an analogue of spatial separation because it locates numbers in a “space” beyond the mental sphere—hence the talk of “logical space” and “Plato’s heaven”. We can’t help thinking of mathematics in quasi-spatial terms, so even here spatial concepts condition our thinking. But in the case of concrete reality, both mental and physical, space holds sway: here intentionality is candidly spatial in nature. Brentano would have done well to acknowledge this fact explicitly, especially since it would enable him to make his points more clearly and decisively.
 Brentano talks as if intentionality were a one-at-a-time thing, but in perceptual cases (and arguably in others) there is a kind of intentional clustering: the mental act takes in many Objects simultaneously, as with vision. Many Objects are laid out in space and intentionality arranges them thus-and-so. Also, it seems wrong to view it as an all-or-nothing thing: we can be more directed to one Object than another, as with the center and periphery of the visual field. Intentionality is not a simple one-one on-off relation (or quasi-relation) but operates more holistically and in a graded manner. What is right in his idea is that the mind is intrinsically directed at the world, though in manifold ways. This is a rather startling discovery because otherwise the mind is quite various (Wittgenstein would have done well to take note of it in his insistence on psychological variety).