The kennels occupied a long brick building designed to resemble the palace in miniature. Inside, the walls were painted with murals of dogs frolicking in the woods and giving chase to a frightened fox while chubby canine cherubim smiled down at them.

Delicate sensitiveness will turn away in fear and disgust as some mouldering daddock is removed, and lizards, sloes, darting beetles, and plodding snails are dazed by the light.

If we do issue a margin call, we may give you a limited time to satisfy the call.

So it is natural to speak of a category of all categories, which we call CAT, the objects of which are all the categories, and the arrows of which are all the functors. This raises genuine problems. Is CAT a category in itself? Our answer here is to treat CAT as a regulative idea; that is, an inevitable way of thinking about categories and functors, but not a strictly legitimate entity. (Compare the self, the universe, and God in Kant 1781.) Of course, general category theory applies to CAT, and this category that we do not quite believe in is the single one that we investigate the most.