Empirically, individuation is distinction, is the separation of all phenomena into exactly one of two classes. The individual 'I' as the source of all distinction ought then to be itself distinguised, but cannot be because everything selected falls into the 'not-I'. The distinction of the 'I' involves no separation or selection, is not subject to the logic of experience. It is unthinkable and yet at the same time must be what is most open, most obvious, most known, prior to thought.