The is from the Mises Institute's _The_Turgot_Collection_

The PDF, page 473, which the introduction to the chapter "To Voltaire" in the Correspondence section.  Tell me this doesn't sound like someone we know.

Turgot corresponded with many of leading thinkers of the Enlightenment, including Voltaire, Condorcet, and Hume, and these letters disclose important aspects of his thought. He strongly condemns the French utilitarian philosopher Helvétius for reducing all human motives to self-interest. To the contrary, human beings display strong sympathy for others. Although morality helps people achieve happiness, it must be based on justice, not a narrow conception of self-interest. Turgot left no doubt about the contents of morality founded on this basis. It requires equal rights for everyone. He warns against confusing this conception with rule by the majority, which can, in his view, lead to a destruction of liberty worse, because less easily changed, than despotism. A prime mistake in thinking about morality is to suppose that nations have interests apart from the individuals who live in them. If one correctly considers the interests of individuals, it is clear that absolute freedom of commerce and avoidance of war are required.

UPB confusion

It seems to me that the majority of objections to Universally Preferable Behavior that I've seen, stem from a belief that morality MUST have a crapload of baggage attached. People can't believe that it's really just "Don't hit, don't steal, use your words." Universalized. Force may be used to stop hitting and stealing, and failing to persuade people to help you is, de facto, ostracism.

Defensive force must be proportional, which, I'm afraid, can only be defined by experiment.