An ignorance of the nature of man

[Below is from a letter written to James Monroe on August 11, 1786:]

It would be to deceive them and ourselves, to suppose that an amity can be preserved, while this right is withheld. Such a supposition would argue, not only an ignorance of the people to whom this is most interesting, but an ignorance of the nature of man, or an inattention to it. Those who see but half way into our true interest, will think that that concurs with the views of the other party. But those who see it in all its extent, will be sensible that our true interest will be best promoted, by making all the just claims of our fellow citizens, wherever situated, our own, by urging and enforcing them with the weight of our whole influence, and by exercising in this, as in every other instance, a just government in their concerns, and making common cause even where our separate interest would seem opposed to theirs. No other conduct can attach us together; and on this attachment depends our happiness.