The Meaning of Relativity Quotes

“One is ordinarily accustomed to study geometry divorced from any relation between its concepts and experience... This is satisfactory to the pure mathematician. He is satisfied if he can deduce his theorems from axioms correctly, that is, without errors of logic. The question as to whether Euclidean geometry is true or not does not concern him... The physicist is concerned with the question as to whether the theorems of geometry are true or not. That Euclidean geometry, from this point of view, affirms something more than the mere deductions derived logically from definitions may be seen from the following simple consideration.”
― Albert Einstein, The Meaning of Relativity

“The only justification for our concepts and systems of concepts is that they serve to represent the complex of our experiences; beyond this they have no legitimacy.”
― Albert Einstein, The Meaning of Relativity