Moreover, just as in the assemblies the ordinary practice is to introduce a law and, if the introduced law is better, to repeal the existing one, so one ought to do in the case of definitions as well: one ought oneself to propose a second definition; for if it is seen to be better, and more indicative of the object defined, clearly the definition laid down will have been demolished, on the principle that there cannot be more than one definition of the same thing.