Is and Ought

In every system of morality, which I have hither to meet with, I have remarked, that the author proceeds for some time in the ordinary way of reasoning... when of a sudden I am surprized to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, 'tis necessary that it should be observed and explained; and at the same time that a reason should be given, for what seemed altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it.
- David Hume, A Treatise of Human Nature (1739-40)

Can you derive a moral judgment from a mere set of facts?

Suppose you see an armed robbery. You see a person with a stocking over his head, a gun in his hand; you see the clerk with her hands up: you see the robber take the money and run. But you do not see the wrongness, the criminality of the act. And for all you really know, the whole occurrence might have been a clever act. It would have looked the same either way, whether it was really wrong, criminally, or not; which just proves that you can't see wrongness. So where does it come from? Not from the facts, but from your sentiments, as Hume calls them, your feelings.

In other words, from "He wore a mask and pulled a gun and took the money and ran" it does not follow that he did something he ought not to have done. You can't go from an is, a fact or set of facts, to an ought, a moral judgment. This was Hume's view, and of course it is consistent with his general skepticism. If all we can know is what we learn from experience, then we can''t know anything about right and wrong, any more than we can know about the material subs-tratum, the self, God, or causality.

In fairness it must be said that Hume tried to salvage ethics by arguing that it is a fact that people universally agree on what qualities are praiseworthy-"temperance,sobriety, patience, constancy, considerateness, presence of mind, quickness of conception and felicity of expression." All these qualities are useful and agreeable, and contribute to the happiness of society, he said. But all this is hardly satisfactory to the person who believes we can know right from wrong and be right about it, whether anyone agrees with us or not.

But is Hume right? Is there no way to derive an ought from an is? Could we not infer from "John is lying" that John is doing something he ought not to do? Or from "Mary is beating her child?" From "Tom is a person" can't we infer all sorts of things about how Tom ought and ought not to behave?

Bibliography

Hume, David .An Enquiry Concerning Human Understanding. The Liberal Arts Press, Inc., New York, 1955.

Hume, David, A Treatise of Human Nature, L.A. Selby-Bigge, ed., Oxford University Press, Oxford, 1888.