For Brentano, intentionality is the mark of the mental: (i) all mental phenomena are intentional, and (ii) all intentional phenomena are mental. This post considers whether there is intentionality below the level of conscious mind, intentionality that can exist without any connection, actual or potential, to conscious mind. If there is, then of course (ii) is false.
Fred Dretske holds that "there is no need to naturalize intentionality" since "It is already a familiar part of our physical world." (Fred Dretske, "If You Can't Make One, You Don't Know How It Works," Midwest Studies in Philosophy XIX, eds. French, et al. (Notre Dame, IN: University of Notre Dame Press, 1994), p. 471.) He means original, not derived or borrowed intentionality of the kind found in words and maps. A map, for example, is about a portion of terrain. But the map’s aboutness is not intrinsic to it, but borrowed from us, who interpret the map as about the terrain. Our interpreting, however, and our comparing of map and terrain, are presumably instances of original intentionality. Dretske's view, then, is that there is original or intrinsic intentionality in natural systems below the level of mind. Not only are mental intentional phenomena really physical, but there are nonmental intentional phenomena. If Dretske is right, we should not be puzzled by mental intentional phenomena, nor should we take them as posing any threat to a thoroughgoing naturalism.
Applying this to Brentano, if Dretske is right, then intentionality cannot be the mark of the mental, that which distinguishes the mental from the physical, for the simple reason that there are both mental and physical instances of intentionality.
The Compass Needle
Dretske invites us to consider a compass the needle of which normally (i.e., when it is functioning properly and is used correctly) points to magnetic (as opposed to geographic) North. Dretske holds that this pointing or indicating is a case of original intentionality: the compass’ “being a reliable indicator does not itself depend on us." (Ibid., p. 471.) It is unlike a map which gets its intentionality from us. So far, so good.
But what makes the needle's pointing to magnetic North an intentional phenomenon? Note that Dretske's claim is not that the needle's behavior is in some metaphorical or 'as-if' sense intentional, but that it is genuinely intentional. Dretske is not making an analogy. He is not saying that the needle's pointing is like my perceiving of yonder mountain. He is saying that the pointing is a genuine case of intentionality: it is intentional in the very same sense that my perceiving is intentional.
The Aspectuality of Intentionality
Now one mark of intentionality is aspectuality. "Anything exhibiting this mark is about something else under an aspect." (Ibid.) The idea is a familiar one. To be aware (whether in perception, imagination, memory…) of something x is to be aware of it as something F. Necessarily, awareness is always awareness of something as something. I am not aware of bare objects, but of objects 'clothed' in properties. Furthermore, even if every F is a G, I can be aware of x as F without being aware of x as G. Indeed, this is so even if necessarily (whether metaphysically or nomologically) every F is a G. Thus I can be aware of a moving object as a cat, without being aware of it as spatially extended, as an animal, as a mammal, as an animal that cools itself by panting as opposed to sweating, as my cat, as the same cat I saw an hour ago, etc. Dretske sees the same structure in compass needles:
Compass needles are about geographical regions or directions under one aspect (as, say, the direction of the pole) and not others (as the habitat of polar bears). This is the same way our thoughts are about a place under one aspect (as where I was born) but not another (as where you were born). (Ibid.)
Note again that Dretske is not making an analogy. He is saying that compass needles are intentional in the same way our thoughts are intentional. He is implying that the aspectuality in the two cases is the same.
Dretske's argument seems to be this:
a. Anything that is about objects under some aspects but not others in the way our thoughts are is an intentional state.
b. Compass states are about objects under some aspects but not others in the way our thoughts are.
Therefore
c. Compass states are intentional states.
The crucial premise in this argument is (b). I will argue that there is no good reason to accept (b).
First of all, to say that the needle is 'about' the polar region as magnetic North is just to say that its pointing in that direction is caused by the magnetic properties of the polar region. What else could 'about' mean here? It is obvious that the needle is not conscious of magnetic North, or of anything else. A compass needle cannot intend or mean anything, any more than a pile of bear scat can intend or mean anything. Of course, one can say such things as, 'This fresh bear scat means that a bear was in the vicinity recently,' but this use of 'means' expresses derivative intentionality, intentionality of the kind which presupposes the original intentionality of minds. And to say that the compass needle's pointing is not 'about' the polar region as bear-inhabited is just to say that its pointing in that direction is not caused by the 'ursine' properties of the polar region, even though the 'ursine' and magnetic properties are coexemplified.
What reason, then, do we have to accept premise (b)? At the very most we have an analogy between the pointing of the needle and the perceiving of the mountain. But let's take a closer look.
The Aspectuality of Intentionality versus the 'Aspectuality' of Causation
It is widely accepted that causation is always causation in respect of specific properties. Thus a knife cuts through tendons in virtue of its sharpness and not in virtue of its being one foot long, but fits into the drawer in virtue of its being one foot long but not in virtue of its sharpness. The knife has both properties. But only one is relevant to its cutting, and only one to its fitting into the drawer.
The properties may even be necessarily coextensive. Triangularity and trilaterality are necessarily coextensive properties: there is no possible world in which one but not the other is exemplified. Nevertheless, it is in virtue of the triangularity, but not the trilaterality, of a piece of metal that I have three bloody points on the palm of my hand.
What Dretske is doing in the quoted passage, then, is assimilating the aspectuality of intentionality to the 'aspectuality' of causation:
INTENTIONALITY: if x is about y, then x is about y under some aspect F, and x can be about y under F without being about y under G even if necessarily every F is a G.
CAUSATION: if x is caused by y, then x is caused by y in virtue of some property F of y, and x can be caused by y in virtue of F without being caused by y in virtue of G of y even if necessarily every F is a G.
No doubt there is an interesting structural analogy between the aspectuality of intentionality and the 'aspectuality' of causation. But does this analogy warrant saying that the compass needle is about a place in the same way (Dretske's words) that our thoughts are about a place? I would think not. If x is like y in the sense that x resembles y, it does not follow that x and y belong to the same genus. A live duck and a wooden decoy duck are alike in all sorts of ways (color, size, shape, buoyancy . . .) but only one of them is a duck.
As I see it, to use ‘about’ and ‘of’ in connection with the pointing of compass needles is a misuse of terms, or at best a misleading idiosyncrasy. It is a semantic stretch that papers over a real difference. But even if we acquiesce in Dretske's terminological mischief, a compass needle is not 'about' or 'of' a place the way consciousness is — on pain of an egregious equivocation. Consciousness presents its object, makes or lets it appear, which is something it could not do apart from consciousness; the needle does not present its 'object,' nor does it make or let it appear. Strictly speaking, the needle's pointing does not have an object; it has a cause.
Nor does the needle present its 'object' under an 'aspect.' One cannot speak literally of aspects here, because nothing is appearing to the needle or to the compass. ‘Aspect’ by its very etymology (ad-spectare) is a mind-involving term. What we have here again is terminological inflation. Furthermore, the needle's pointing to magnetic North is a purely physical, publicly observable, pointing. In this sense, consciousness does not 'point' to its object; it is rather the presentation of its object to a subject whose subjectivity and point of view are not publically accessible.
I cannot examine your states of consciousness to see what they are about the way I can examine compass needles, weather vanes, etc. to see what they are pointing at. And I do not examine my own states of consciousness to see what they are about. I may examine a state of my body such as a skin rash to inquire about its underlying cause, but I never examine my conscious experiences to see what they are of or about. Experiences are not signs of, or pointers to, their objects. Husserl refuted this 'sign-theory' of consciousness long ago. (Cf. Edmund Husserl, Logical Investigations vol. II, trans. J. N. Findlay (New York: The Humanities Press, 1970), pp. 593-596.)
Original, Derived, and 'As If' Intentionality
Thus it is only by equivocating on such key words as 'about' and 'aspect' that Dretske can come to ascribe original intentionality to compass needles, clouds, smoke, tree rings, and the like. But there is another mistake that must be avoided, namely, that of inferring that if something is not a case of derived intentionality, then it must be a case of original intentionality. For there is the possibility that it is a case of what Searle calls ‘as-if’ intentionality, which of course is not intentionality at all. A good example is a thermostat which, as we say, ‘senses’ a change in room temperature. Such talk is harmless in everyday life but misleading to some philosophers. Clearly, the thermostat does not literally sense anything; it is not conscious of a change in temperature. ‘Sensors’ in general, whether electrical, mechanical, electromagnetic, photoelectric, etc., do not literally sense anything. Sentience is a mode of consciousness, and no such contraption as a thermostat is conscious.
Or do you want to say that a chocolate bar melting in a hot car literally feels the heat? Yet thermostats behave as if they sense a change in temperature; it is as if they possess intentional states. The same holds for the pointing of the compass needle. From the fact that this is not a case of derived intentionality, it does not follow that it is a case of original intentionality. What follows is that it is not a case of intentionality at all, but merely behaves as if it were a case of intentionality. As Colin McGinn puts it, "When we think we are conceiving of content in the absence of consciousness we are really treating a system as if it were conscious, while simultaneously denying that this is what we are up to."(Colin McGinn, The Problem of Consciousness (Oxford: Blackwell Publishers, 1991), p. 33. I should add McGinn does not quite endorse this view.)
To deny the distinction between intrinsic and 'as-if' intentionality would be to embrace the view that all natural phenomena are intentional. For all natural phenomena have causes, and causation, as noted, is always in respect of properties. But it is surely obvious that not all natural phenomena are intentional in the very same way conscious phenomena are intentional. If they were, all natural entities would be conscious, which is absurd. Not even the panpsychist is committed to this. Even if everything is composed of conscious items, it does not follow that everything is conscious.
One might be tempted to say that there are two kinds of intentionality, or two kinds of content. There is unconscious intentionality and there is conscious intentionality. In this way one might hope to avoid the absurd conclusion that every natural phenomenon exhibits conscious intentionality. McGinn speaks in this connection of "two species of content, personal and subpersonal…" He continues:
I doubt that the self-same kind of content possessed by a conscious perceptual experience, say, could be possessed independently of consciousness; such content seems essentially conscious, shot through with subjectivity. This is because of the Janus-faced character of conscious content: it involves presence to the subject, and hence a subjective point of view. Remove the inward-looking face and you remove something integral — what the world seems like to the subject. (Ibid. p. 34)
This is right, and spells the doom of the naturalization project, the attempt to account for such intentional phenomena as beliefs and desires in wholly physicalistic terms. For what it implies is that there can be no third-person, wholly objective, understanding of conscious intentionality. But without an understanding of conscious intentionality, there is no understanding of mind.
But even more fundamentally, that there are two kinds of original intentionality is not a coherent proposal. If there are two kinds or species of original intentionality, conscious and unconscious, then there must be a genus of which they are the species. But what could this genus be? We saw, pace Dretske, that the pointing of the compass needle is not about magnetic North in the same sense that a thought is about magnetic North. It is only by equivocating on 'of' and 'about' that one could think otherwise. Thus there is no generic aboutness. If there is no generic aboutness, there can be no kinds or species of aboutness. Clearly, what we must say is that unconscious intentionality is no more a kind of intentionality than artificial leather is a kind of leather. In 'artificial leather,' 'artificial' does not specify, but shifts, the sense of 'leather.' Similarly, 'unconscious' does not specify, but shifts, the sense of 'intentionality.' Unconscious intentionality, then, is as-if intentionality. And McGinn's subpersonal contents are as-if contents.