Douglas Portmore on Philosophy and Moral Disagreement

https://www.youtube.com/watch?v=oBq-2vpbS60

8:15 - 13:24

"Philosophy is unique as a discipline in that you do not have to accept any disciplinary assumptions or methods in order to count as doing philosophy. You can do philosophy so long as you are investigating certain questions like whether we have free will, whether there are moral facts, and you don't have to accept Rene Descartes' method of doubt or foundationalism or coherentism or X-phi or any other particular methodology to count as doing philosophy. You also don't have to accept any kind of particular assumptions, like you don't have to accept classical logic, or the law of non-contradiction, or the principle of bivalence to count as being a philosopher.

Now that's different from other disciplines. You don't count as doing science if you don't employ the scientific method. You don't count as doing science if you don't accept or assume that there's a world that exists independently of our perceiving it, a world that we can learn about via our empirical observations. And that's why we don't teach creationism in science class, and we don't look at the argument from design in science class. To count as science you have to do empirical investigation and creationism doesn't involve doing that kind of empirical work, and the argument from design for the existence of God doesn't do that kind of empirical work, so it just doesn't count as science.

Same thing with mathematics: if you don't accept Euclid's axioms and you don't accept classical logic as the method of inferring certain theorems and postulates from those axioms using classical logic, then you just don't count as doing geometry.

So philosophy is unique in that in order to count as doing philosophy you don't have to accept any particular assumptions or even particular methodology. And this is why philosophers don't converge on views in the way that scientists and mathematicians do. And this is why, with respect to philosophical disagreement, you don't have a resolution of these philosophical questions in the way that you have a resolution in mathematics and in science. . . . 

Why is there so much moral disagreement? Because we do moral inquiry via philosophical inquiry. And when we do philosophical inquiry, we are not required to start from any certain assumptions, and we are not required to follow any particular methodology. . . . 

So we've had three explanations for moral disagreement: One explanation is the disagreement is due to the fact that there are no moral facts for us to agree on. The second explanation is that although there are moral facts for us to agree upon, we fail to agree because some people are just ignorant of those facts. And then a third explanation is that the reason why there is so much moral disagreement is because moral disagreement is done in the mode of philosophical inquiry, and the nature of philosophical inquiry is such that it doesn't result in convergence on certain particular views.

I think the third is the best explanation, and to see that, notice that we don't find that there's any greater disagreement about moral issues among philosophers than there are about other philosophical questions among philosophers. So we find that the kind of disagreement we have with respect to morality is the same as the kind of disagreement we have with respect to whether there's free will . . . how to solve the mind-body problem, and so on and so forth. So it's no surprise then that we find that there's so much moral disagreement . . ."