What Do We Mean By Rationality - LessWrong 2.0 by lesswrong.com
Notes
Beliefs that conform to a coherent probability distribution, and decisions that maximize the probabilistic expectation of a coherent utility function, are called “Bayesian.”—ref
You certainly shouldn’t ignore something just because you can’t define it. I can’t quote the equations of General Relativity from memory, but nonetheless if I walk off a cliff, I’ll fall. And we can say the same of cognitive biases and other obstacles to truth—they won’t hit any less hard if it turns out we can’t define compactly what “irrationality” is.—ref ❧ This seems to be a problem that permeates my epistemological inquiry; sure, we cannot define “knowledge” very well. Thus we must use context and prior knowledge to use the definition in practice, but can ad hoc make it precise. It seems to me that a definition of a concept is a normative concept, we are not asking “which definition matches this phenomenon,” we are asking “which phenomenon matches this definition?” In the example of fire, our definition will only make sense in context to seeing the real thing. Perhaps a definition is not so much a selection of a phenomenon, but an emphasis of certain properties, an implicit proposition.
there are questions of how to think that seem not quite answered by either probability theory or decision theory—like the question of how to feel about the truth once you have it—ref ❧ It seems to me like this should fall under rationality. This is “how should I feel,” which is under decision theory. Perhaps that is this example only. It would be different if the question was “how do I feel about the truth.” Let us examine the claim with a bit more muddled terms in an attempt to understand. I could say that “how to feel about truth” might be contingent on the truth itself, but this is analogous to an action being contingent on the states and outcomes.
“rationality” should be consistent under reflection—“rationally” looking at the evidence, and “rationally” considering how your mind processes the evidence, shouldn’t lead to two different conclusions.—ref
- Epistemic rationality: systematically improving the accuracy of your beliefs.
- Instrumental rationality: systematically achieving your values.—ref