Truly man is a marvellously vain, diverse, and undulating object. It is hard to found any constant and uniform judgement on him.
Certes, c'est un subject merveilleusement vain, divers, et ondoyant, que l'homme. Il est malaisé d'y fonder jugement constant et uniforme.
Original text (French)
Notes from Wikiquote
Man in sooth is a marvellous, vain, fickle, and unstable subject. (tr. Cotton, rev. W. Hazlitt, 1842)