This paper attempts to be a contribution to the epistemological project of explaining
complex conceptual structures departing from more basic ones. The central thesis of the paper
is that there are what I call “functionally structured concepts”, these are non-harmonic concepts
in Dummett’s sense that might be legitimized if there is a function that justifies the tie between
the inferential connection the concept allows us to trace. Proving this requires enhancing the
russellian existential analysis of definite descriptions to apply to functions and using this in
proving the legitimacy of such concepts. The utility of the proposal is shown for the case of
thick ethical terms and an attempt is made to use it in explaining the development of natural
numbers. This last move could allow us to go one step lower in explaining the genesis of
natural numbers while maintaining the notion of abstract numbers as higher order entities.
