The cogito is Descartes’ famous I think, therefore I am, which he thought proved that we existed, indubitably. Previously I have discussed how his cogito holds up in terms of modern philosophical thought, and, in brief, it does quite well, although a modern philosopher would have probably made it more formal and given it more detail than Descartes did, something I have tried to rectify, at least to some small extent. Of course, unlike Descartes, we wouldn’t think that this knowledge was completely apriori, since it rests on certain principles about how truth works, specifically how true conclusions can be deduced from true premises. And the nature of truth is something that, although we may have strong intuitions about it, can only be known for certain by making observations about how it works in the external world. In any case, instead of scrutinizing the cogito here I will instead take it for granted, and investigate the connections between it and consciousness.
Obviously the cogito cannot be deduced by every conscious system. The fact that we can deduce the cogito is dependant on our ability to think formally (at least in some language) and to be able to make deductions. But there is no reason to think that every conscious system must have these abilities, and thus not every conscious system can deduce the cogito. However, it does seem that there is an important connection between the cogito and consciousness in the other direction; that if something can deduce the cogito it must be conscious.
But, although it may seem reasonable to claim this, it remains to be shown that a system that can deduce the cogito must be conscious. To do that I must first clarify what I mean by deduce in this context, in order to rule out some obvious counter examples, for instance a printer that is programmed to print out “I think, I am” over and over, or a system that works with statement on a completely formal level being given the statement “I think” and arriving at the conclusion “I exist”. Obviously the second is closer to deducing the cogito than the first, but it is only doing part of the deduction, the part that requires reasoning ability. The complete deduction of the cogito requires the ability to come up with the statement “I think” without any outside prompting (or at least to be able to affirm the truth of the statement based on the evidence available). And this is something that neither the printer nor the deduction system can do. But we can, and certainly any conscious being that is sufficiently intelligent can as well.
So why must the ability to deduce the cogito in this way imply that the system that can deduce it is conscious? Well, there are two ways to argue for this. One is by appeal to our own situation with regards to consciousness. The cogito is one of the most foundational truths that we have available to us. Although there is not much else that can be built off of it, it itself is immune to doubt, because the very act of being able to doubt affirms its conclusion, because in order to doubt we must exist. Everything else about ourselves is more open to doubt than it. For example, I can more readily doubt that I am who I think I am, that I have some ability that I think I have, than I can doubt that I exist. But being conscious is not something that we are supposed to be able to doubt, it is supposed to be evident, indubitably, to us. Thus there are two possibilities. The existence of the cogito can logically imply that we are conscious, consciousness can be equally indubitable for some other reason, or consciousness may not be as certain as existence. If you make consciousness less certain than existence then consciousness essentially evaporates. This is because it would become rational to doubt that we ourselves were conscious, because we have problems identifying what consciousness is in objective terms. And if we can’t find it, and it is rational to doubt its existence, then it would seem natural to then conclude that we weren’t, in fact, conscious, but that we only thought that we were. Hopefully this seems as absurd to you as it does to me. The second possibility, that it has an independent reason for being indubitable, which seems unlikely to me as well, simply because I can’t see how to construct such an indubitable basis for it. One possible way to attempt to establish that it is indubitable is to simply say that it is self evident that we are conscious, that we simply know it. But that is not a valid argument, because by the same logic you could conclude that anything you want existed (god, unicorns, ect) as long as their existence felt indubitable to you, which is silly. A second possibility is to construct a cogito-like proof, reasoning that if you think you must be conscious, since thinking is conscious, but this just begs the question, since to prove that you are conscious you are assuming that you have conscious acts. (And can’t even a mindless computer “think” in some sense when it churns through sentences in a deduction program, even though it isn’t conscious?) And thus it seems that the ability to deduce the cogito must imply consciousness, since we have shown that the other two possibilities are unacceptable.
Of course, as I mentioned above, there is another, more direct, way to argue that the ability to deduce the cogito implies consciousness, which is good, since the method presented above might seem rather roundabout, and thus suspicious. To do that we must pull apart the initial premise of the cogito, that “I think”. This means that the system that deduces the cogito is in some sense a subject, because it conceives of itself as a unitary entity extended through time. And secondly the fact that it thinks that it thinks (heh), means that it has experiences, or at least thinks that it has experiences. Which means that it naturally would conceive of itself as conscious. If you described your experience of being conscious (that you have a stream of experiences, and so on) the system would conclude that it too was conscious (if it previously had no opinion on the matter), since it too has a stream of experiences, just like you, although the nature of its experiences may differ from you. Again, I appeal to the basic indubitably of consciousness, that if a system honestly thinks of itself as conscious when you explain what consciousness is to it, then it is conscious. I should hope this principle is self-evident, because it is why we think that we are conscious, someone explained what consciousness was, and then we realized that we too were conscious. So to doubt that such a system is conscious would be to doubt that you (or at least everyone else) was conscious. Since that is unacceptable we must thus conclude that the system that deduces the cogito is conscious.