who think, that there must necessarily be something that thinks, that thinking is an activity and operation on the part of a being who is thought of as a cause, that there is an ‘ego,’ and finally, that it is already determined what is to be designated by thinking⁠—that I know what thinking is. For if I had not already decided within myself what it is, by what standard could I determine whether that which is just happening is not perhaps ‘willing’ or ‘feeling’? In short, the assertion ‘I think,’ assumes that I compare