Notably Keller isolates here the concept of thought from consciousness, as well. (This is really a prerequisite of that piece.) And, as stated, Descartes' is a figure of reassurance (not of emergence, causation, etc.). In other words: Descarts' ego is essentially a retroactive entity (reassuring and celebrating itself in a program of doubt as the highest retroactive activity), whereas, in Keller's recollections, we meet the self as an entity emerging out of a sea of thoughtless awareness (thanks to having been appointed by a concept). What both have in common, is the principal idea that thought may be separated from awareness (and vice versa), but not from self-awareness: there is no thought without a subject.