Ferdinand de Saussure established linguistics as an independent science in the light of a brand new conception of language in early twentieth century. Our basic claim, which we try to justify in our paper, is that Saussure, while establishing linguistics, was implicitly defying the classical approach in philosophy of language. Thus, we tried to bring to light the approach that Saussure tacitly withstands and the philosophers from which such approach arose from. Consequently, we identified that Saussure put forward the following three major objections against classical approach of philosophy of language in his lessons and writings: 1) A linguistic sign cannot be reduced to a signifier, seeing not only that a linguistic sign does not only consist of a signifier, but also that a signifier is not identical to a word. 2) The assumption of pre‐language ideas is invalid. 3) “Signification” is not a “substitution” phenomenon. We checked out these objections in relation to the views of his counterparts in the history of philosophy, whom Saussure never named.