For instance a young man in a family understands that he has the responsibility for his mother and father, who are old. It is a duty, and not only a duty but a virtue on his part, that he should devote all that he earns, and give every service that he can render them in their old age. His idea of virtue is that if he can be helpful to his aged parents with money or with service, he will devote both to them, and he considers that to be a virtue. That is the ideal thing for him to do, so he does it. Perhaps he does not perceive anything beyond it, but what he does perceive is virtue in his eyes. And that is why he wishes to do it, and in it lies his satisfaction.