 Some historical discussions of the representational properties of mind (e.g., Aristotle De Anima, Locke 1689/1975, Hume 1739/1978) seem to assume that nonconceptual representations – percepts (“impressions”), images (“ideas”) and the like – are the only (or at least the main) kinds of mental representations, and that the mind represents the world in virtue of being in states that resemble things in it. On such a view, all representational states have their content in virtue of their sensory phenomenal features. Powerful arguments, however, focusing on the lack of generality (Berkeley Principles of Human Knowledge), ambiguity (Wittgenstein 1953) and non-compositionality (Fodor 1981d) of sensory and imagistic representations, as well as their unsuitability to function as logical (Frege 1918/1997, Geach 1957) or mathematical (Frege 1884/1953) concepts, and the symmetry of resemblance (Goodman 1976), convinced philosophers that no theory of mind can get by with only nonconceptual representations construed in this way. (For more discussion, see the entry on  nonconceputal mental content.)