Typed Letter Signed
ONE OF EINSTEIN’S CLEAREST STATEMENTS OF HIS PHILOSOPHY OF SCIENCE.
Responding to a question by R.L. Worrall on the relationship between science (physics) and reality and between science and matter, Einstein replies, in part [translated from the original German]:
“All physics is realistic in so far as it starts from the hypothesis of a reality which is independent of perception and thought. It is no longer materialistic inasmuch as it does not acknowledge matter as the irreducible conceptual basis of the physical theoretical system.”
In this letter, Einstein is affirming “realism” as the philosophic foundation of physics, and further asserts that this realistic basis is not to be conceived as “matter.” Einstein is here responding to R. L. Worrall’s solicitation of his view of “philosophical materialism” (which takes matter to be the fundamental reality and, by extension, the basis of mind). Einstein’s diplomatic response is essentially a rebuttal of Worrall’s “philosophical materialism”: for Einstein, “matter” is itself a construct of mind. Einstein here clearly holds that theoretical physics is an invention of the mind in its encounter with Nature/Reality (which is independent of mind), and “matter” is merely one among multiple possible viewpoints and conceptualizations.
In asserting that matter is no longer taken to be “the irreducible conceptual basis” of physics, Einstein is signaling that theoretical physics has in fact moved beyond the exclusive concept of matter to a higher, more unifying, idea—a development which Einstein’s own work did much to foster and advance.
Berlin: 18 March, 1930. To R. L. Worrall. One page on Einstein’s letterhead. Some repair along the folds of the letter. Signed “A. Einstein” at end. Einstein letters with such important statements about his understanding of science are rare.