Language as Set Theory

The revolution in our understanding of the logic of names began with a basic question: Where do the meanings of words live? There are two likely habitats. One is the world, where we find the things that a word refers to. The other is in the head, where we find people’s understanding of how a word may be used. For anyone interested in language as a window into the mind, the external world might seem to be an unpromising habitat. The word cat, for example, refers to the set of all the cats t...

 The Cuttlefish Uses Art to Hunt

The cuttlefish is mostly soft-bodied; the crab is all armor. As the cuttlefish approaches, the medieval-looking crab snaps into a macho posture, waving its sharp claws at its foe’s vulnerable body. The cuttlefish responds with a bizarre and ingenious psychedelic performance. Weird images, luxuriant colors, and successive waves of what look like undulating lightning bolts and filigree swim across its skin. The sight is so unbelievable that even the crab seems disoriented; its menacing gestu...