Abstract
Classical philosophical notions, such as conceptual truth, analyticity, and a priori
knowledge, have recently re-entered the mainstream philosophical debate, after fifty
years of depreciation. This paper illustrates how such notions are reintroduced and
discussed in a current debate on the nature of concepts, along with the idea that a
concept is individuated by an implicit definition. This traditional Neopositivist device
has recently been redeployed by writers such as Peacocke, Horwich, and Boghossian.
Implicit definitions raise a variety of interesting issues, from semantics to epistemology:
how can they succeed in fixing a concept’s semantic property, if not by convention?
are they analytic, in the Quinean sense? Do they provide with a priori knowledge?
Which constraints are appropriate, for some formulation genuinely to pick up
the semantic property of a concept?.