The most unsettling thing at the end of Arthur C. Clarke’s 2001: A Space Odyssey is not that David Bowman has become something other than human. It is that he has acquired dominion before deciding what to do with it. The novel enlarges intelligence without settling the purposes intelligence should serve.

Spoilers for the novel follow.

The first safe night

Moon-Watcher begins as a hungry creature who thinks he might reach the Moon by finding a sufficiently tall tree. Curiosity precedes an adequate account of distance.