Kant does argue that we have an indirect duty to ourselves to treat beautiful objects in non-human nature humanely (as we would say), a duty arising from the fact that because of our general obligation to try to be moral we should do everything in our power to do so and therefore should not damage ‘a natural predisposition’ that, ‘though not of itself moral... greatly promotes morality or at least prepares the way for if; this is the basis of Kant’s argument, alluded to above, in §17 of the ‘Doctrine of Virtue’ of the Metaphysics of Morals (6:443).