ABSTRACT
Tibbles the cat is sitting on the mat. Tibbles minus any one of 1,000 hairs is also a cat. If any one of those hairs had been missing we should still have had a cat there on the mat. So it seems we have 1,001 different cats on the mat, for Tibbles has precisely the hairs he does at the time, and so cannot be identical with any of the cats with only 999 hairs.
