One of the founders of modern logic, G. Frege, has insisted on the variety of meanings of the little word ""is."" He explicitly distinguished four such meanings (sheer predication or subsumption, identity, assertion, and existence); a fifth meaning (subordination) follows from Frege's new theory of predication. It is part of the Fregean doctrine that special symbols corresponding to different meanings of ""is"" are to be used. Such distinctions have been strongly challenged by J. Hintikka, in a twofold way: theoretically and historiographically. Neither challenge is regarded as successful. Behind the conflict on ""is"" two opposite conceptions of language may be perceived: language as culture versus language as nature (""natural language"").