@kennethamy,
Tracyfan_1,
I am assuming that the question that you are asking is coming from
Essay Concerning Human Understanding, specifically on Locke's conception of identity and consciousness in Book II. If not, I don't know what text you are trying to extrapolate this information from, so please post the text and preferably the citation numbers. But to sum up what you are asking, you want to find a problematic instance in identity and consciousness.
To Locke, personal identity is neither immaterial nor material substance. Simply, when Locke differentiates two possible substances, a substance in itself or a particular substance, he does not categorize the personal identity in that way. Instead, personal identity lay in the realm of consciousness (specifically, look to chapter xxvii, Book II,
Essay) Locke is breaking with the norm here, which is that the sameness of person is inextricably connected with the sameness of substance. Locke in fact thinks that the sameness of a person had absolutely nothing to do with the sameness of the substance, except for the fact that they both have the sameness in consciousness. Consciousness for Locke is essentially "the perception of what passes in a man's own mind." So now we get into a very abstract and potentially complex series of examples that will elaborate on your question. This is how I have understood the argument, so please bear with it.
The self as Locke describes it (xxvii, Book II,
essay) is a cognizant being with the aptitude for reason and reflection (from book 1) and understands the fundamental substantial qualities of itself. A self is also aware of itself in one place and another, both times linked with its own consciousness. I want to explain this with this two dimensional analogy.
Picture yourself in a green park. At one end of the park there is a solitary bench. At the other end, there is another bench but it is shaded by a great oak tree. You start off at the solitary bench. Take a snapshot of that image, but as a snap shot, record that you are Person 1 at Time 1 (i.e. P1,T1) now move across the park to the bench shaded by the great oak tree. Take a second snap shot and record Person 2 at Time 2 (i.e. P2,T2). Are you the same person? Locke would say that: (P1,T1<--(s)-->P2,T2)<--(iff)--> (P2--(c)-->P1). You at the time of the first snapshot (P1,T1) are the same as you at the second snapshot (P2,T2) if an only if You at the time of the second snapshot were conscious of all things done from the moment of the first snap shot.
But doesn't this seem unreasonable though. It would require that the person at the instance proceeding the former remember
everything