Generalizing

John McCaskey has an interesting, short, clear blog post up about scientific induction.

He begins by drawing a distinction between general statements and universal statements. "Paper burns" is a general truth, he says, but perhaps not a universal truth. You know, there is wet paper - that won't burn! And there are special varieties of flame-resistant paper, designed not to burn.

'“Paper burns” is a generalization that does not mean “All paper burns,” “Some paper burns,” “Most paper burns,” “All other things being equal, paper burns,” or even “Within a given context of knowledge, all paper burns.”'

I have a question here. I agree that "paper burns" doesn't mean exactly the same as "some paper burns" in everyday speech. But surely "paper burns" implies "some paper burns" at a bare minimum.

He goes on:

'“Generally” comes from the Latin “generis,” meaning “belonging to the kind.” What is generally true is true because the subject is the kind of thing it is. Balls roll and fire burns, because there is something about balls and paper that makes them roll and burn.'

That seems fair enough. He goes on to make the case that:

Scientific induction
involves definitional reconstruction.

So you throw whales out of "fish" -
because they're more mammal-ish.

(Once I tried to throw a whale.
Man, it was an epic fail.)