De Agricultura

For he says that the swine is an unclean animal, because it divides the hoof and does not chew the cud, just as he has pronounced the camel unclean for the contrary reason because it chews the cud and does not divide the hoof. But as many animals as partake of both these qualities are very appropriately described as clean, because they have avoided impropriety in both the aforementioned particulars. For division without memory, and care, and a diligent examination of what is best, is but an imperfect good; but the combination and union of the two in the same animal is a most perfect good.