Hume, David—Along with Locke and Berkeley, Hume (1711-1776) is classified as one of the three principle British empiricist philosophers. He taught that knowledge is comprised of sense data; there is no a priori knowledge; existence is identical to our own ideas; there is no objective connection between cause and effect, and there is no mind, self, or spiritual substance apart from a bundle of sense impressions and ideas in our heads. See Empiricism.