Even when the experts all agree, they may well be mistaken. - Bertrand Russell

I cannot escape from the conclusion that the great ages of progress have depended upon a small number of individuals of transcendent ability.

I shall keep it [the manuscript] by me until the end of May for purposes of revision, and of adding malicious foot-notes.

The process of philosophizing, to my mind, consists mainly in passing from those obvious, vague, ambiguous things, that we feel quite sure of, to something precise, clear, definite, which by reflection and analysis we find is involved in the vague thing that we start from, and is, so to speak, the real truth of which that vague thing is a sort of shadow.