state- ment of Reid's thesis. But when presenting the actual argument, he concludes, "Therefore there must be a natural language before any artificial language can be invented: Which is what was to be demon- 4 There is a close affinity between what Reid calls "natural signs" and what Grice calls "natural meaning." To illustrate natural meaning, Grice used the example "those spots mean measles" (1957). To illustrate natural signs, Reid used examples such as "smoke is a natural sign of fire" and a certain countenance on a human face is "a natural sign of anger" (1764: 177). Reid's "natural language of mankind" might thus be regarded as a subset of Gricean natural meaning, where the signs in question are those features of human behavior and countenance that signifyfeedback, I thank Christian Hegele, Kevin Kuhl, Patrick Rysiew, and Nicholas Wolterstorff. Special thanks go to An- gelo Turri. This research was supported by the Social Sciences and Human- ities Research Council of Canada and an Ontario Early Researcher Award. John Turri | 18 Chomsky, Noam. 1957. Syntactic structures. The Hague: Mouton. Chomsky, Noam. 1966. Cartesian linguistics: a chapter in the history of rationalist thought. New York: Harper & Row. Cuneo, Terrence, and Rene van Woudenberg, eds. 2004. The Cam- bridge companion to Thomas Reid. Cambridge: Cambridge University Press. Grice, H. P. 1957. Meaning. The Philosophical Review 66.3: 377–388. Grice, H.P. 1969. Utterer's meaning and intention. The Philosophical Review 78.2: 147–177. Immerwahr, John. 1978. The development of Reid's realism. The Monist 61: 245–256. Jensen, Henning. 1979. Reid and