<p>The stimulus for this thesis came from a quite unexpected source. Originally I embarked on a comparative study of the two philosophers primarily responsible for the divergence of the Continental and Anglo-American traditions of language based philosophy: Ferdinand de Saussure and Gottlob Frege. But when I began a careful reading of Saussure’s Course in General Linguistics (1974 – the Course) I was struck by the extent to which his synchronic theory of language appeared to reflect an awareness of linguistic evolution as analogous to biological evolution. That seemed to me to be particularly interesting for two reasons. First, I was aware of the empirical success that linguists and biologists have had in the late twentieth century in exploiting this analogy, particularly in tracing the geographical origins of ethnic groups (Cavalli-Sforza, 2000). Second, Saussure is usually identified with a view of language as something essentially arbitrary and conventional – something essentially human (Saussure, 1974, p. 16). By that account linguistic evolution would seem to have little in common with natural evolutionary processes. Yet far from rejecting the analogy, Saussure seemed to be taking a position within it, promoting a view of linguistic evolution that was akin to a contemporary Darwinian understanding, as opposed to a more archaic view, of biological evolution (Saussure, 1974, p. 4). The questions then arose: to what extent is Saussure’s theory of language a theory that could underpin and explain the linguistic-biological analogy? To what extent should it be such a theory? And what does the linguisticbiological analogy suggest about the philosophical appropriation of Saussure’s theory? These are the guiding questions of this thesis. The answers I advance make for what I hope is an interesting and even provocative re-reading of Saussure’s theory of language.</p>