Opposable thumbs

But the pride of the hand is the fully opposable thumb. Without thumbs, our hands would be only a marginal improvement over a pirate’s hook. Other animals, with their thumbless extremities, can merely paw at the world, or butt and scrape it with their hooves. But because we humans have thumbs, we can seize hold of it and manipulate it to our ends.

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Well, a hand is obviously for eating. A hand is for caressing. A hand is for making fists and bludgeoning. A hand is for making tools and wielding them. A hand is lascivious: it is for groping and tickling and teasing. Hands are for making sense: we wave them around to amplify what we are saying. My own hands are for all of the above, but these days they are mostly for thumbing through books and typing.

Our hands are tools, but evolution did not shape them for one single thing. The hand is not the biological equivalent of a hammer or a screwdriver; the hand is a multipurpose tool like a Swiss Army knife—it is for many things.