Also, re: Pitt the Younger. It's ironic that he should be considered as the philanthropic abolitionist of the slave trade. Well, that is, his contemporaries would have considered it quite ironic. The list of what we would call his human rights violations and what the French Revolutionaries and the "patriots" and "radicals" of his own country would refer to as violations of natural rights and the droit des gens (ius gentium) is not a short one. Of course, Pitt didn't believe in human rights (that's what makes him a counter-revolutionary), but there was a form of the droit des gens that was generally considered as established by the 18th century, even by traditional monarchies. Here is one principle: when two powers are at war, one power has the right to seize shipments of weapons to the other aboard neutral ships; otherwise neutral ships were to be left alone under the principle of free ships, free goods. Pitt extended the goods liable to be considered as weapons and confiscated to foodstuffs, thereby creating the "right" to starve a population of non-combattants. This was important not only because this was exactly the policy that he pursued (in this particular case by seizing American grain shipments to France), but also because by his declaration he turned this violation into a principle.