What, if anything, is a rabbit?

Darren Naish [via Pharyngula] has a lovely article about the morphology and taxonomic and phylogenetic relationships of Lagomorpha, rabbits and hares. In the course of the piece, Naish quotes one Albert Wood, from 1957, whose paper with the title of this post starts out

The title of this paper is slightly modified from that of an article I encountered some years ago, which appeared to be approaching the problem of the relationships of the Lagomorpha, or rabbits and their relatives, from the most basic point of view. This paper, entitled “Gibt es Leporiden?”, seemed to be questioning the very existence of such animals. Investigation showed, however, that the question involved was not whether members of the family Leporidae existed, but whether rabbit-hare hybrids did. Since then, I have met no one who questions the existence of rabbits and hares, and I have been reluctantly forced to accept them.

They don't write papers like that any more. I, too, question the reality of rabbits. Just because.