Albert Camus said this quote

This heart within me I can feel, and I judge that itexists. This world I can touch, and I likewise judge that it exists. There ends all my knowledge, and the rest isconstruction. For if I try to seize this self of which I feel sure, if I try to define and to summarize it, it is nothingbut water slipping through my fingers. I can sketch one by one all the aspects it is able to assume, all thoselikewise that have been attributed to it, this up bringing, this origin, this ardor or these silences, this nobility orthis vileness. But aspects cannot be added up. This very heart which is mine will forever remain indefinable tome. Between the certainty I have of my existence and the content I try to give to that assurance, the gap willnever be filled. Forever I shall be a stranger to myself. In psychology as in logic, there are truths but no truth.Socrates' Know thyself has as much value as the Be virtuous of our confessionals. They reveal a nostalgia atthe same time as an ignorance. They are sterile exercises on great subjects. They are legitimate only in preciselyso far as they are approximate.