Men are inconsolable ...

Men are inconsolable concerning the treachery of their friends or the deceptions of their enemies; and yet they are often very highly satisfied to be both deceived and betrayed by their own selves.
Men are inconsolable concerning the treachery of their friends or the deceptions of their enemies; and yet they are often very highly satisfied to be both deceived and betrayed by their own selves.

Quotes from the same author

A true friend is the greatest of all blessings, and that which we take the least care of all to acquire.
In friendship as well as love, ignorance very often contributes more to our happiness than knowledge.
A true friend is the most precious of all possessions and the one we take the least thought about acquiring.
He is a truly virtuous man who wishes always to be open to the observation of honest men.
There are no events so disastrous that adroit men do not draw some advantage from them, nor any so fortunate that the imprudent cannot turn to their own prejudice.