Smallville, Season 5

Professor Fine:
Why else would the son of family farmers be defending such a man?

Clark:
It's a long story, but Lex's not the man you make him out to be.

Professor Fine:
Well, you know, Groucho Marx said there was only one way to find out if a man is honest: ask him. If he says yes, then he must be crooked.

Clark:
I would think a college professor would be quoting Karl Marx, not Groucho.

Professor Fine:
German philosophy is easy. Comedy's hard.