  Reid’s final criticism is that the Memory Theory is committed to the absurdity that identity consists in something that has no continued existence (Essays, 278). Reid and Locke agree that memory, consciousness, thought, and other mental operations have no continued existence. They are fleeting and non-continuous. But they also agree that identity, and in particular personal identity, requires a continued existence over time. As Locke puts it, “one thing cannot have two beginnings of Existence, nor two things one beginning” (Locke, Essay, Book II.xxvii.1). But these commitments are jointly inconsistent with the thesis that personal identity consists in memory.