What do I mean by "morality isn't logical"? I mean in the same sense that mathematics is logical but literary criticism isn't: the "reasoning" we use to think about morality doesn't resemble logical reasoning. All systems of logic, that I'm aware of, have a concept of proof and a method of verifying with high degree of certainty whether an argument constitutes a proof. As long as the logic is consistent (and we have good reason to think that many of them are), once we verify a proof we can accept its conclusion without worrying that there may be another proof that makes the opposite conclusion. With morality though, we have no such method, and people all the time make moral arguments that can be reversed or called into question by other moral arguments. (Edit: For an example of this, see these posts.)
Without being a system of logic, moral philosophical reasoning likely (or at least plausibly) doesn't have any of the nice properties that a well-constructed system of logic would have, for example, consistency, validity, soundness, or even the more basic property that considering arguments in a different order, or in a different mood, won't cause a person to accept an entirely different set of conclusions. For all we know, somebody trying to reason about a moral concept like "fairness" may just be taking a random walk as they move from one conclusion to another based on moral arguments they encounter or think up.
In a recent post, Eliezer said "morality is logic", by which he seems to mean... well, I'm still not exactly sure what, but one interpretation is that a person's cognition about morality can be described as an algorithm, and that algorithm can be studied using logical reasoning. (Which of course is true, but in that sense both math and literary criticism as well as every other subject of human study would be logic.) In any case, I don't think Eliezer is explicitly claiming that an algorithm-for-thinking-about-morality constitutes an algorithm-for-doing-logic, but I worry that the characterization of "morality is logic" may cause some connotations of "logic" to be inappropriately sneaked into "morality". For example Eliezer seems to (at least at one point) assume that considering moral arguments in a different order won't cause a human to accept an entirely different set of conclusions, and maybe this is why. To fight this potential sneaking of connotations, I suggest that when you see the phrase "morality is logic", remind yourself that morality isn't logical.
I like this splitup!
(From the great-grandparent.)
I think I want to make a slightly stronger claim than this; i.e. that by logical discourse we're thinning down a universe of possible models using axioms.
One thing I didn't go into, in this epistemology sequence, is the notion of 'effectiveness' or 'formality', which is important but I didn't go into as much because my take on it feels much more standard - I'm not sure I have anything more to say about what constitutes an 'effective' formula or axiom or computation or physical description than other workers in the field. This carries a lot of the load in practice in reductionism; e.g., the problem with irreducible fear is that you have to appeal to your own brain's native fear mechanisms to carry out predictions about it, and you can never write down what it looks like. But after we're done being effective, there's still the question of whether we're navigating to a part of the physical universe, or narrowing down mathematical models, and by 'logical' I mean to refer to the latter sort of thing rather than the former. The load of talking about sufficiently careful reasoning is mostly carried by 'effective' as distinguished from empathy-based predictions, appeals to implicit knowledge, and so on.
I also don't claim to have given morality an effective description - my actual moral arguments generally consist in appealing to implicit and hopefully shared reasons-for-action, not derivations from axioms - but the metaphysical and normative claim is that these reasons-for-action both have an effective description (descriptively speaking) and that any idealized or normative version of them would still have an effective description (normatively speaking).
Let me try a different tack in my questioning, as I suspect maybe your claim is along a different axis than the one I described in the sibling comment. So far you've introduced a bunch of "moving parts" for your metaethical theory:
But I don't understand how these are supposed to fit together, in an algorithmic sense. In decision theory we also have missing modules or black boxes, but at least we specify their types and how they interact wi... (read more)