As I have described it here and here intentionality is best viewed as something that can be said of the mind, or a way of describing some of the connections between the mind and the world, but the intentional relation itself is not part of the mind. Believing there to be a necessary connection between a thought and the real world objects it is directed at is a form of externalism, and since we know that externalism implies that the mind is epiphenomenal, and because the mind is not epiphenomenal, we conclude that there is no such necessary connection. It certainly feels like there is though.* When we perceive an object it feels as if we are being presented with object itself, not some representation of the object. Why do we interpret our experience this way if there is no necessary connection?
To explain the intentional feeling I must make a few preliminary observations. The first is that we only have access to our experiences / the contents of consciousness, a point that was made evident by phenomenology. The second is that the idea of a separately existing world is not itself contained in our perceptions, but rather something we deduce from them. I suspect children realize the existence of an independently existing world when they realize that objects don’t go away when they can’t be seen, which obviously leads to the idea that the objects themselves are somehow existing independently of the person who perceives them. The fact that our perceptions can sometimes be “wrong” (i.e. later perceptions disagree with earlier ones, or different senses disagree at the same time) further reinforces the idea that there is more to what exists than our perceptions of it. However, since we only have access to this independently existing world through our perceptions we begin to identify it with them, thus leading to the feeling of intentional directedness that accompanies them.
Now some will say that this intentional feeling is not really directed at the world but at whatever is the cause of our perceptions. That might be true when we are talking about what is at the other side of the intentional relation, but because the intentional feeling is caused by a certain conception of the world it is not the case that we feel our perceptions to be directed at whatever is out there. More specifically we conceive of the world as something that has an “independent existence” (meaning that it needs nothing else to exist, unlike perceptions which require a perceiver), as mentioned previously. If the world were shown to be simply a simulation this would be a denial that the trees we perceive are real, independently existing, trees. We would then consider the feeling that our perceptions were directed at real trees to be false, not that our feelings of intentionality were really directed at virtual trees all along.
Of course there will always be some who will argue that we “really” feel our perceptions to be directed at whatever they are really intentionally related to, and that it is simply faulty introspection that leads us to believe that they are directed at one thing or another. But, if you really believe that our awareness of the experience of intentional directedness can be deceived in this way there is no reason to suppose that it must really be directed at anything at all. In fact it would make the most sense to say that our real feeling of intentional directedness is not actually directed at anything at all, and that it simply appears to us that we feel our perceptions to be directed something; certainly this is the simplest solution. It also reveals how strange it is to suppose that how something feels to us might not be how it “really feels”, since how something feels to us is all that matters in terms of consciousness and the mind in general, leaving nothing for the how it “really feels” to do. (see also)
Although this account of where our feeling of intentional directedness comes from probably won’t convince any externalists that the intentional relation is not in the mind, it should defuse worries that an internalist account of the mind somehow leaves unexplained the intuition that mental activities are directed at some specific thing in the world.
* Another reason to believe that our experience of perception as containing some connection to the external world is inaccurate is a thought experiment described by Horgan, Tienseon, and Graham in their paper “Internal-World Skepticism and the Self-Presentational Nature of Phenomenal Consciousness”. First we consider a person who lives a normal life, and thus feels that their experiences about trees are about real trees, and any decent description of intentionality will agree with this feeling. However, we could kidnap this person and imprison them in a virtual world (without their knowledge), which is as far as they can tell indistinguishable from the real world. Since they don’t know that they are in a virtual world they will still feel that their experiences of trees are about real trees (as they have no reason to think differently), but now a decent theory of intentionality should tell us that their experiences are really about virtual trees. Since it is possible then for the feeling of intentionality to disagree with real intentionality it is logical to conclude that the feeling of intentionality arises from some other source, and not from the real intentional relation.