Laws of cat

Posting pictures of cats has become a popular thing to do among bloggers (just enter "cat blog" in Google's image search and see, or try this). Rather than join that parade, I thought I'd post some generalizations about cats.

I started thinking about cat generalizations when confronted by a common line of argument about laws of nature in the philosophy of science. This says a law of nature is a statement that is always true everywhere, and that does not refer to an individual. That is, laws are about classes of things, not particular things.

When I ran across this idea, I said to myself: biological species are particular things, individuals, not classes*; the species came into existence at particular time, it will eventually pass away, and it has a particular location in space (this planet), so it's not a class of things. And yet, I can come up with general statements about cats that sure look like laws of nature. Here's an example:

All cats are always on the wrong side of every door.

Here's another:

The cat gets the middle two-thirds of the bed.

Corollary 1. (Size invariance). This is true no matter what size the bed is. If you want to sleep by yourself in a space 3 feet wide (the width of a standard single bed), you need a bed 18 feet wide in order to get a 3-foot border around the middle two-thirds of the bed.

Corollary 2. (Number invariance). It doesn’t matter how many cats there are; each cat gets the middle two-thirds of the bed.

Here's another law about cats:

Each cat is the most important cat in the world.

So much for philosophy.

*Michael Ghiselin. 1974. A radical solution to the species problem. Systematic Zoology 23:536-544.