"A mathematician is a person who can find analogies between theorems; a better mathematician is one who can see analogies between proofs and the best mathematician can notice analogies between theories. One can imagine that the ultimate mathematician is one who can see analogies between analogies."

--Stefan Banach

See also here: http://mathoverflow.net/questions/7155/famous-mathematical-quotes

So, can someone give an example of an analogy between analogies?