The memory criterion holds that personal identity requires the ability to remember or quasi-remember past experiences, or to be linked to them by an overlapping chain of memories.

Neither move gets us far, however, as both the original and the modified memory criteria face a more obvious problem: there are many times in our pasts that we cannot remember or quasi-remember at all, and to which we are not linked even indirectly by an overlapping chain of memories. There is no time when you could recall anything that happened to you while you dreamlessly slept last night. The memory criterion has the absurd implication that you have never existed at any time when you were unc