This article is aimed to rephrase and critique the arguments presented by Joseph LaPorte about the truth of theoretical identity statements in natural sciences. LaPorte is classified as an essentialist who accepts the real kinds, but he denies the essence of the kinds to be discovered. His arguments are based on the vagueness of the terms of kinds. In his view while science progress we convention (not discover) what is related to the kinds. I evaluate LaPorte's arguments and show they (...) can be applied only for the border terms in scientific theories and so the generalization of the claim is not defensible. (shrink)