The observance of justice, though useful among them, is not guarded by so strong a necessity as among individuals; and the moral obligation holds proportion with the USEFULNESS.

All politicians will allow, and most philosophers, that reasons of state may, in particular emergencies, dispense with the rules of justice, and invalidate any treaty or alliance, where the strict observance of it would be prejudicial, in a considerable degree, to either of the contracting parties.

But nothing less than the most extreme necessity, it is confessed, can justify individuals in a breach of promise, or an invasion of the properties of others.
In a confederated commonwealth, such as the Achaean republic of old, or the Swiss Cantons and United Provinces in modern times; as the league has here a peculiar UTILITY, the conditions of union have a peculiar sacredness and authority, and a violation of them would be regarded as no less, or even as more criminal, than any private injury or injustice.
The long and helpless infancy of man requires the combination of parents for the subsistence of their young; and that combination requires the virtue of chastity or fidelity to the marriage bed.

Without such a UTILITY, it will readily be owned, that such a virtue would never have been thought of.
[Footnote: The only solution, which Plato gives to all the objections that might be raised against the community of women, established in his imaginary commonwealth, is, [Greek quotation here].
Scite enim istud et dicitur et dicetur, Id quod utile sit honestum esse, quod autem inutile sit turpe esse.

[De Rep lib v p 457 ex edit Ser].