I hold with the Swiss psychologist Jean Piaget that the process of learning mathematics is itself a process of rediscovery. A similar view was expressed by the logician Ludwig Witgenstein, asserting in the preface to his famous *Tractatus Logico-Philosophicus* that he would probably not be understood except by those who had already had similar thoughts themselves.

— A Unified Language for Mathematics and Physics

— David Hestenes

— Clifford Algebras and their Applications in Mathematical Physics

2013.02.18 Monday ACHK