There’s the ideal beauty of youth and health, which never really changes, and is always true. There’s the ideal beauty of movie stars and advertising models, the beauty-game ideal, which changes its rules all the time and from place to place, and is never entirely true. And there’s an ideal beauty that is harder to define or understand, because it occurs not just in the body but where the body and the spirit meet and define each other….

That must be what the great artists see and paint. That must be why the tired, aged faces in Rembrandt’s portraits give us such delight: they show us beauty not skin-deep but life-deep.

~ Ursula Le Guin via Brainpickings