Ethics and observation

"Ethics and observation" is the title of the first chapter in Harman's (very readable) introduction to ethics. He is trying to explain what makes ethics problematic in a way that science or math is not. Harman is a particularly good person for me to be reading, because he was a student of Quine's. Quine was the author of the "indispensability argument" in mathematics, which is something that I'm focusing research on.

Quine was an empiricist--a position that I can't think of any good way to characterize, so I'll just say that it's the view that the justification of any knowledge has to come from observation. Empiricism makes a lot of good sense. After all, how do I know that I'm justified in believing that my computer is sitting on a table? Isn't it just that I can observe that my computer is on the table! So just generalize from there, and suppose that all knowledge is like my knowledge about where my computer is. But accounting for math was a sore spot for empiricists right from the beginning. Cuz math doesn't seem to be true because of any empirical observation! You don't look at anything to try to prove that 2+5=7, you just figure it out. Empirical observation seems to be worthless when it comes to math. (I'll post a stronger argument for that at some point; Frege made some good ones, and they were directed against J.S. Mill).

So math is difficult for empiricists. If you're an empiricist, you owe us an account of how math fits into your empiricist framework. Take the logical empiricists. They said that all math is logic, and all logic is empty of content (and here they were inspired by Wittgenstein). So since it's devoid of content, you don't have to worry about how we know things about math; it's empty anyway (does that make sense? def not the way I wrote it). But everything else needs empirical justification.

Quine, who was originally an advocate of this view, destroyed it in his landmark paper "Two Dogmas of Empiricism." What he did with math was, actually way cooler and more radical. He argued that math was actually empirical, and so it's just like all other knowledge. But he didn't do this in a kinda stupid way. Rather, he argued that lots of math is absolutely necessary for science; and that therefore we should believe that math is true. That's a one sentence version of the "indispensability argument for the existence of mathematical objects". Another way of putting it is that inference to the best explanation is the way we justify scientific beliefs, and the truths of math are part of the best explanation of the world in a deep, unavoidable way. This is the argument that I'm going to be looking at more closely in the thesis, if all goes according to plan.

The question is, is ethics different from scientific and mathematical knowledge in this regard? At first glance, obviously it's different. Ethics doesn't seem to be tied to our best explanation of the world, it doesn't seem necessary for scientific practice. In this first chapter Harman makes this argument a bit more carefully, and tomorrow I'll present his argument as a first shot way of distinguishing between ethics and math in an empiricist framework.

Well, I'm really tired and this post didn't really go anywhere. But tomorrow I'm going to be looking at Harman's chapter more carefully.