" Conjecture or hypothesis must come before observation or perception: we have inborn expectations; we have latent inborn knowledge, in the form of latent expectations, to be activated by a stimuli to which we react as a rule while engaged in active exploration. All learning is a modification (it may be a refutation)of some prior knowledge and thus, in the last analysis, of some inborn knowledge. "

― Karl Popper , Unended Quest: An Intellectual Autobiography