A body has one function with many directions.

I like that; "The purpose of the body is to move the stomach to a new foraging location."

I mentioned it to Matt, who didn't get the joke.

Accepted, the body has functions (level 0) and it has itself (level 1) and it has 'return from deviation from levels 0 and 1' which is level 2, then there is 'regulator for level 2' which is level 3, then there is 'regulator for level 3' which is level 4, then there is the 'stabilisation system for level 4', which is level 5 then finally we get to level 6:

The human endocannabinoid system (HECS). Imagine your body has a puppeteer working it, and that puppeteer has a puppeteer working it, and so on, until you get to the guy at the top, the HECS. No matter how much the guy at the top rattles his jig, the guy at the bottom never stops breathing.

You can even cut the strings of the uppermost jig and the guy at the bottom doesn't stop breathing (even if he does seem a little bit grumpy).