Ethical Theory Spring 2021

Moral and Scientific Observations


Gilbert Harman tries to show that ethics are subjective by contrasting ethical thought with the sciences. He maintains that the observations that we make when examining the natural world are best explained as encounters with objective reality. By contrast, he believes, moral observations are best explained as the products of our upbringing and psychology. Our moral thoughts would be the same even if there were no moral facts to observe but the same is not true of observations in the sciences.

What is an observation?

An observation is something you experience. Harman contrasts two different observations:

  1. Your observation that it is wrong for the hoodlums to burn the cat (Harman 1977, 4).

  2. A physicist’s observation of a vapor trail in a cloud chamber (Harman 1977, 6).

Harman thinks that all observations require what he calls theories. Your mind needs to interpret the colored splotches that appear on the back of your eyeballs.

In the first case, you have theories about animals, pain, and morality that come into play when you observe that burning the cat is wrong.

In the second case, the physicist has theories about how the cloud chamber works and what atoms are like that come into play when he observes a proton making the vapor trail.

Without these theories, neither observer would make the observations that they did.

What is the difference?

Here is Harman’s chief claim.

observation plays a role in science that it does not seem to play in ethics. The difference is that you need to make assumptions about certain physical facts to explain the occurence of the observations that support a scientific theory, but you do not seem to need to make assumptions about any moral facts to explain the occurence of the so-called moral observations I have been talking about. In the moral case, it would seem that you need only make assumptions about they psychology or moral sensibility of the person making the moral observation. In the scientific case, theory is tested against the world. (Harman 1977, 6)

That is, you need to assume that there really is a proton that causes the physicist to observe the vapor trail in the cloud chamber.

By contrast, you do not need to assume that cat burning is really wrong to explain the observation that what the hoodlums did to the cat was wrong. Harman thinks that the beliefs of the observer alone can explain that observation.

Questions for discussion

You can challenge Harman’s argument from either direction.

  1. You can say that the physicist’s psychology explains the physicist’s observations. Look at all the false physical theories that have been “confirmed” by experiments over the years, for instance.

  2. You can say that you do need to assume that causing pointless suffering really is wrong in order to explain the observation that what the hoodlums did was wrong.

In our discussion, I want to talk through how these objections would go. That is, I want to talk about how could we fill them out, how would Harman reply, and what we ourselves think.

Update on science

I made mush of an example that I brought up to illustrate something Liam said in response to Soo Bin. As it happens, I just read a lovely explanation of the exact example I was trying to describe.

French Astronomer Urbain Le Verrier was already famous for discovering the planet Neptune. In 1859, he started to work on a different problem. He carefully tracked the movement of the planet Mercury, and noticed it wasn’t moving how it was supposed to according to Newton’s equations. The problem of the perihelion precession of Mercury bothered Le Verrier a lot; his best theory was that there must be a hidden planet exerting a gravitational pull too. Le Verrier called the hypothetical planet “Vulcan”.

It took until 1915 for Albert Einstein to find the real answer: Newtonian physics was incomplete and the world was weirder than it seemed; he proposed a new theory of General Relativity.

Here is a slightly more complex explanation.

The author, Arieh Kovler, recounts this example to introduce a possible new discovery: a fifth fundmental force in addition to gravity, electromagnetism and the strong and weak nuclear forces.

Update on cat burning

Harman doesn’t go into much detail about why moral observations are fully explained by the upbringing and psychologies of the people who make them. He could have borrowed Mackie’s argument from relativity to help his case. Specifically, attitudes about cruelty to animals vary across cultures. That suggests that the best explanation of the observation “that’s wrong” really is cultural, namely, people from a different culture thought “that’s funny.”

Here’s an example of how officers in the English Civil War “diverted and cheered their men with military tricks and jokes” (Donagan 2008, 280).

I should acquaint your honour, what frequent alarums we gave them [the Parliamentary army besieging the town -mjg] by fire-balls, lights upon our steeple, by dogs, cats, and outworne horses, having light matches tyed about them and turned out upon their workes; whereby we put the enemy in such distraction, that sometimes they charged one another: this recreation we had in the middest of our besieging (Letter from Bar. Scudamore to Lord Digby circa 1645, reprinted in Duncumb 1804–1882, 1:279)

In other words, one way they kept their spirits up during the siege was by setting animals on fire and sending them towards the other army. The author of the letter calls that recreation.

Key Points

  1. The relationship between theories and observations.

  2. The difference between moral and scientific observations, according to Harman.


Donagan, Barbara. 2008. War in England 1642-1649. Oxford: Oxford University Press. doi:10.1093/acprof:oso/9780199285181.001.0001.
Duncumb, John. 1804–1882. Collections Towards the History and Antiquities of the County of Hereford. Vol. 1. Hereford.
Harman, Gilbert. 1977. The Nature of Morality. New York: Oxford University Press.