Against Euclidianism in Moral Philosophy

Philosopher Michael Huemer describes a regrettable detour in the history of philosophy:

Something unfortunate happened early in the history of philosophy, which is: Philosophers discovered Euclid’s Elements which is this wonderful mathematics book, wonderful book of geometry. People used to have to study it in school in their geometry classes.

It starts with these geometrical axioms and then proves all these geometrical theorems. And it’s very convincing. There are all these things are very convincingly proved, and interesting claims as well that are not obvious before they’re proved.

And philosophers looked at it and said okay so that’s how all human knowledge should be. And then they start thinking that philosophy should be that way and so we’re going to lay down the philosophical axioms and so here are the axioms of ethics, okay?

Well, to burst the philosophers’ bubble, most of human knowledge does not work like Euclid’s Elements. Even geometry doesn’t work like Euclid’s Elements. What actually happened was Euclid’s Elements came thousands of the years after the beginning of geometry.

Geometry started with a series out much more concrete formulas for calculating areas and volumes and perimeters which were mostly empirically derived, or they were guesses are, or things that sort of seemed intuitively right to people.

It started in ancient Egypt. It was mostly for surveying reasons that people needed geometry, they needed to know how much land somebody had.

It was thousands of years after the beginning of geometry that Euclid came along and, having seen all of these little formulas and these little geometrical discoveries, then he tried to systematize it.

Geometry did not start by somebody saying “Well, let’s see , you know, a point is something that has no parts, is indivisible and any two points have a straight line between them…” It started out with all these little formulas and then somebody tried to systematize it.

So now in moral philosophy we are not yet at the stage of somebody being able to write down the axioms, we’re still at the stage of collecting the little formulas. And if somebody tries to set down the axioms before you’ve done sufficient work, before thinking enough about more concrete propositions they are almost certainly going to get it wrong.

– transcribed from Huemer’s talk on his common sense moral defense of libertarianism.

The upshot for libertarians is that we should generally not base moral arguments on supposed axiomatic principles, for instance the NAP (as it is usually considered), because we're quite likely to get our supposed axioms wrong. And in fact we find that it is too easy to come up with counter-examples to the NAP for it to be viable as an axiom.

What should we base moral arguments on? We should base them on uncontroversial common sense moral views. The NAP is highly controversial, but the view that aggression is usually unjustified is not. Whether a given instance of aggression is justified may be initially controversial, but the idea that aggression needs a moral justification is not - hardly anyone thinks it's okay to aggress without a sufficiently good reason.

These uncontroversial views may seem weak, and they are weaker claims that, say, an axiomatic NAP. But Huemer shows that they are sufficient ground for strong moral arguments.

Almost everyone agrees that no private individual would be justified in compelling others to pay for services they had not agreed to pay for, in normal circumstances. The burden of argument is thus shifted to defenders to of supposed legitimate state authority – they must now demonstrate why the situation with respect to the state is different and how it overcomes the normal presumption that such behavior is unjustified.

It turns out this is very difficult for the statist to do, and thus we have a strong foundation for launching effective moral arguments against the state.

Here is the talk:

John T. Kennedy