“I shall not hesitate to state here in a few sentences my epistemological credo.... I see on the one side the totality of the sense experiences and, on the other, the totality of the concepts and propositions that are laid down in books.... The system of concepts is a creation of man, together with the rules of syntax, which constitute the structure of the conceptual system.... All concepts, even those closest to experience, are from the point of view of logic freely chosen posits, just as is the concept of causality, which was the point of departure for this inquiry in the first place.”

(from Einstein's Autobiographical Notes) (ref. TBA)