Defeasible Generalization

"Stubb then in a plain, business-like, but still half humorous manner, cursed Pip officially; and that done, unofficially gave him much wholesome advice. The substance was, Never jump from a boat, Pip, except--but all the rest was indefinite, as the soundest advice ever is. Now, in general, Stick to the boat, is your true motto in whaling; but cases will sometimes happen when Leap from the boat, is still better."

From Moby Dick, Chap. 93: The Castaway