The idea that continuity of identity is carried by memory seems clearly wrong. If it were possible to swap your entire 'book' of memory with someone else, so that you had their memories and they had yours, would you become them and they become you? No, not at all! It would be like exchanging the films shown on two different screens and saying that therefore the screens had been interchanged. In other words whatever it is is that is meant by witnessing is not a function of memory. Surely witnessing is maintained even if you forget everything as soon as it happens, or if nothing happens. But in the memory swap experiment would either party feel that something strange had just occurred? Well, apart from your present body looking quite different from the way you remember it? It is very tempting to fuse identity with memory, and perhaps everything assertable about identity does have a connection with memory, but identity in its deepest sense, is not what can be asserted - it has nothing to do with the _ 'I am'. Actually the real point here, not very well argued, is that contrary to identity depending on memory (as a hypothetical collection of contents, a book) it is memory that depends on identity. The only reason you can claim some remembered event as belonging to your experience is because of a timeless identity between you the witness now and you the witness then. This identity is a completely different kind of 'thing' than any content such as might belong to the catalogue of memory, it is pre-experiential.