Albert Einstein insists that his epistemology made his discovery of relativity possible. He believed it was his understanding of the relationship of experience and reason that allowed him to reconsider certain “truths” of physics. Specifically, he believed that reality and thought were independent but related, and that conceptual systems are independent of but conditioned by experience. Failure to understand the relation between experience and reason had, Einstein believed, limited progress in science. His understanding of the relation, on the other hand, enabled him to formulate relativity theory and therefore provides one example of the relevance of philosophy to scientific inquiry.