[FOM] Origin of Notion of Characteristic Function

[Richard Heck]

Does anyone know to whom the notion of a set's characteristic function 
might be credited? It is my view that Frege's treatment of truth-values 
as objects ultimately amounts to identifying concepts with their 
characteristic functions, and I am wondering if this idea was original 
to Frege or if perhaps he got it from someone else.

Thanks,
Richard

-- 
-----------------------
Richard G Heck Jr
Romeo Elton Professor of Natural Theology
Brown University