This paper is about the meaning of tolerance in science from a philosophical perspective (e.g. that of Carnap, Quine, and Davidson) as related to virtues and the context of changing languages and paradigms of science. The notion of "science" is used in the English sense of the term; that is as denoting the natural sciences and mathematics, but not the humanities and the social sciences. The common roots of tolerance in the Modern philosophy of science is found in the Enlightenment, particularly the work of Voltaire, whom both Quine and Popper refer to as an authority on the issue.