Attempts to explain Peirce’s various classifications of signs have been a preoccupation of many Peirce scholars. Opinions are mixed about the sense, coherence, and fruitfulness of Peirce’s various versions, particularly the latter ones. I argue here that it is not a fruitful enterprise, even if sense could be made of them. Although Peirce makes his motivations for the classification of the sciences fairly explicit, it’s hard to find Peirce’s reasons for sign classification. More importantly, I try to make the case (...) that such classifications are premised on a reductionist framework of semiosis that is contrary to the irreducible triadic character of signs that Peirce otherwise espouses. The reductionism is the result of Peirce’s use of certain models for his sign classifications, in particular, Mendeleev’s periodic table. I suggest that the remedy for the reductionism is to re-emphasize the processual and functional view of semiosis, rather than to focus on particular classes of signs. Corresponding to the three triadic conditions of semiosis, I argue that signs function to inform, represent or refer, and interpret, and that understanding these three function and how they interrelate may prove to be a more fruitful approach to sign analysis than sign classification. (shrink)