 Norman Kretzmann calls the claim that “words in their primary or immediate signification signify nothing but the ideas in the mind of him that uses them” (III.2.2) “Locke’s main semantic thesis” (see Kretzmann 1968:179). This thesis has often been criticized as a classic blunder in semantic theory. Thus Mill, for example, wrote, “When I say, ‘the sun is the cause of the day’, I do not mean that my idea of the sun causes or excites in me the idea of day” (Mill 1843: bk 1, ch. 2, § 1). This criticism of Locke’s account of language parallels the “veil of perception” critique of his account of perception and suggests that Locke is not distinguishing the meaning of a word from its reference. Kretzmann, however, argues persuasively that Locke distinguishes between meaning and reference and that ideas provide the meaning but not the reference of words. Thus, the line of criticism represented by the quotation from Mill is ill founded.