  Later, cleaving (or perhaps clinging) to his “all necessity is de dicto” starting point, he consistently refused to countenance any de re necessities. He strenuously resisted the essentialism that became fashionable following the work of Putnam and Kripke in the 1970s, but his reasons for doing so were not always to the point. In his argument against essence-based de re necessities Ayer would say that “Caesar is necessarily human” is not true, since he could have called his dog “Caesar”. Here he lost sight of his own insistence (in the Introduction to the 2nd. Edition of LTL) that necessary truths were expressed in a language whose terms had already been assigned meaning and reference, so changing the reference of “Caesar” is irrelevant to the necessary truth of a sentence employing the term with its ‘normal’ reference.