Knowing That I Think
What is it that I know when I know that I think? One view is that I know of myself that I have the attribute of thinking: I recognize that I (a self) instantiate a certain property. This requires that I must know of my existence in order to know that I think. The knowledge that I think therefore presupposes knowledge of the proposition that I exist, which precludes it from serving as a premise in the Cogito, on pain of circularity. It also raises the question of how I know that I exist, if not by knowing that I think: is this existential knowledge somehow primitive and independent of my knowledge of my mental states? Do I just perceive my existence directly? Yet (as Hume pointed out) I don’t seem to have any impression of myself as such. I seem to be referring to myself and predicating a property of that self, but my knowledge of the referent is puzzling. Do I really know the truth of a subject-predicate proposition in which the subject refers to myself and the predicate ascribes a property to that self?
A famous response to the Cogito insists that I am only entitled to claim knowledge of the proposition that there are thoughts going on, from which it doesn’t follow that I exist as an entity over and above my thoughts. But we need to be more specific than that if we are to capture the import of the proposition in question: it is thinking in me that I know to exist, not thinking happening anywhere to anybody. But then we are back with the self and the problems that arise with that. You might think we could fix the problem by invoking the indexical expressions “here” and “now”: what I know is that there is thinking going on here and now. But again this doesn’t give us any distinction between my having thoughts and someone else having thoughts. How do we tie the reference down without invoking the self as thinking thing? I suggest we appeal to the demonstrative “this consciousness”: what I know is that there is thinking going on in this consciousness. When I say that I know that I think I am saying that I know there is thought occurring in this consciousness, where the demonstrative refers to a certain consciousness (mine). The consciousness in question may be quite brief—perhaps the duration of the thought—and it may also contain other mental states, such as perceptions and emotions. What is important is that it is not identical to the self: I have a state of consciousness but I am not that state of consciousness. I may persist for longer than it does, and I am not a state but a thing—the bearer of a conscious state. The concept expressed by “this consciousness” is far less committal than the concept expressed by “I”: it is simply that which currently exists as a particular state of consciousness. I can refer to this overall state, and when I attribute thinking to myself that is what I do. The proposition that I know is thus equivalent to the proposition that this state of consciousness includes thinking—which makes no reference to a self at all. There is thus something peculiar and misleading about the use of “I” in expressing what I know: the self is not really being referred to at all–the word “I” is not occurring as a “referring expression”. The sentence paraphrases out into a sentence about a state of consciousness.
This analysis has a desirable result from the point of view of the Cogito: it allows it to escape triviality. For now we don’t have to accept that the premise presupposes the conclusion by referring to the very thing the Cogitoseeks to establish. The Cogito should read as follows: “There is thinking going on in this consciousness, therefore I exist”. Here the premise does not contain the conclusion; it is a substantive step from the presence of thinking in a particular (state of) consciousness to the conclusion that there is a thinking self. The self (Descartes’ thinking thing) is what has states of consciousness—or what is conscious; it is not consciousness itself. (The Cogito does not read, “I think, therefore my consciousness exists”.) In order to know the premise of the Cogito we have to know that two things exist—thoughts and the consciousness in which they occur. But neither of these logically presupposes the existence of the self. The self comes in via the principle that consciousness requires a bearer or a subject or an underlying substance (as it might be, the brain or an immaterial entity). Of course, that principle can be questioned (and historically has been), but at least the Cogito cannot be convicted of roundly begging the question, under this interpretation of it. And that seems intuitively right, because we don’t react to the Cogito by immediately complaining that the premise presupposes the conclusion; we naturally interpret the premise in such a way that the conclusion is a substantive extra step. All it is really saying is that a certain consciousness (this one) contains a certain attribute, with no reference made to a self as such. The Cogito may be a non sequitur, but it is not a tautology.
The expression “this consciousness” is a very peculiar demonstrative, which only comes into use in attributions of self-knowledge; it has little to no public use. We use the word “I” when we want to talk about ourselves in the presence of others—referring to a certain person—but the words “this consciousness” refer to something invisible to others and not of their concern. Each person uses it to refer to his or her own private inner awareness as it evolves through time; it is the hook on which to hang self-attributions of mental states. When we think that we think we think something of the form, “There is thinking going on in this consciousness”—which we logically could do without ever using the word “I”. We refer thereby to an immediately given reality: our total phenomenological state at a given time. No doubt this entity is obscure and elusive (we are talking about consciousness after all), but it is what encompasses or grounds our more specific mental states. I would not wish to say that it is simply the set of all my current mental states (the “bundle theory” of consciousness), preferring to view it as a unitary mental reality—a kind of field of awareness. But we needn’t enter into the metaphysics of consciousness in order to recognize that the demonstrative “this consciousness” has a referent and that this referent plays a role in self-knowledge. Whenever I know something mental about myself I tacitly employ the demonstrative “this consciousness” in my thought. The logical form of “I think”, as it is used in the Cogito, is an existential quantification over thoughts combined with a locative designation of a specific field of consciousness: “There are thoughts located in this field of consciousness” (similarly for doubts, pains, etc). Thus I am not logically required to know of the existence of the self in order to know that I think, only of the existence of thoughts and consciousness. So we don’t need to postulate some kind of direct non-inferential knowledge of the self in order to explain my knowledge that I think.