We must likewise observe, that the several principles, already established concerning the validity of conventions in general, agree to public treaties, as well as the contracts of individuals. In both, therefore, there must be a serious consent, properly declared, and exempt from error, fraud, and violence. If treaties, made in those circumstances, be obligatory between the respective states or sovereigns, they are also binding with regard to the subjects of each prince in particular. Under the former head we may rank all those treaties, by which we are purely and simply engaged to do no injury to others, but, on the contrary, to perform all the duties of humanity towards them. Among civilized nations, who profess to follow the laws of nature, such treaties are not necessary.
Duty alone is sufficient, without a formal engagement.
Both are made either in time of war, or in full peace. These treaties are made either with a view to commerce, or to confederacy in war, or in short to any other matters. What we have been saying sufficiently shows the meaning of unequal treaties. And these are, when the promises are either unequal, or such as lay harder conditions on one of the parties, than on the other. However, though these, and other similar conditions, do not diminish the sovereignty, it is certain that such treaties of inequality are often of so delicate a nature, as to require the greatest circumspection, and that if the prince, who is superior to the other in dignity, surpasses him also considerably in strength and power, it is to be feared, that the former will gradually acquire an absolute sovereignty over him, especially if the confederacy be perpetual.