> Why not [just use] functions as first class data?

Because they're not. When you copy an object, you don't copy all of its methods; instead, you copy all of its function pointers.

I mean there are languages that have functions as first class data. Not wrapped up in objects. Think Lisp, Scheme, Haskell. Even Python can do this - otherwise map and filter would hardly work.

Btw: I really meant 'just functions', nothing around them.