To compare to Montaigne on friendship, this excerpt from this piece on Machiavelli in the London Review of Books:
Anyone who might see our letters … and see their variety, would be greatly astonished, because at first it would seem that we were serious men completely directed toward weighty matters and that no thought could cascade through our heads that did not have within it probity and magnitude. But later, upon turning the page, it would seem to the reader that we – still the very same selves – were petty, fickle, lascivious, and were directed towards chimerical matters.”
Reminds me of a passage from Christopher Hitchen’s autobiography, where he describes a regular lunch he and some friends, all famous writers, had once a week in London. Over the wine they would play a rhyming game, competing to string together as much profanity as possible.