Locke on Consciousness, Personal Identity and the Idea of Duration

It is as undeniable as it is unhelpful to say that for Locke personal identity consists in the identity of consciousness. It is undeniable because he just comes out and says as much in passages like the following: “[T]he same consciousness being preserv’d. . .the personal Identity is preserv’d.” (II.xxvii.13) It is unhelpful, however, for two reasons: First, it is unclear what consciousness is; what portion of a mind’s mental activity at a time is its “consciousness”? Second, even if we knew what, of all the myriad things going on in my mind now is my “consciousness” and we knew what, of all the myriad things that went on in the mind of a child who, in 1976 was forced to wear an embarrassing sailor suit, is his “consciousness”, it would still be unclear what conditions must be satisfied for the two “consciousnesses” to be the same. The simple memory theory of personal identity—the theory according to which later and earlier person-stages are stages of the same person just in case the later can remember the experience of the earlier—tries to solve both problems at once. The theory equates consciousness with any conscious act of awareness and then insists that two acts of awareness are the same in the relevant sense if they have the same content, if they are awarenesses of the very same thing. What makes my “consciousness” and the sailor-suitwearing boy’s the same, on this view, is that we are both aware of the same event, and in the same way