Opening Example: Teleology

When people say “the heart’s purpose is to pump blood” or “a pencil’s function is to write”, what does that mean physically? What are “purpose” or “function”, not merely in intuitive terms, but in terms of math and physics? That’s the core question of what philosophers call teleology - the study of “telos”, i.e. purpose or function or goal.

This post is about a particular way of approaching conceptual/philosophical questions, especially for finding “True Names” - i.e. mathematical operationalizations of concepts which are sufficiently robust to hold up under optimization pressure. We’re going to apply the method to teleology as an example. We’ll outline the general approach in abstract later; for now, try to pay attention to the sequence of questions we ask in the context of teleology.

Cognition

We start from the subjective view: set aside (temporarily) the question of what “purpose” or “function” mean physically. Instead, first ask what it means for me to view a heart as “having the purpose of pumping blood”, or ascribe the “function of writing” to a pencil. What does it mean to model things as having purpose or function?

Proposed answer: when I ascribe purpose or function to something, I model it as having been optimized (in the sense usually used on LessWrong) to do something. That’s basically the standard answer among philosophers, modulo expressing the idea in terms of the LessWrong notion of optimization.

(From there, philosophers typically ask about “original teleology” - i.e. a hammer has been optimized by a human, and the human has itself been optimized by evolution, but where does that chain ground out? What optimization process was not itself produced by another optimization process? And then the obvious answer is “evolution”, and philosophers debate whether all teleology grounds out in evolution-like phenomena. But we’re going to go in a different direction, and ask entirely different questions.)

Convergence

Next: I notice that there’s an awful lot of convergence in what things different people model as having been optimized, and what different people model things as having been optimized for. Notably, this convergence occurs even when people don’t actually know about the optimization process - for instance, humans correctly guessed millenia ago that living organisms h...

Reductionism

See also