However powerful education may be in forming men's sentiments, there must, in such a matter as morality, be some deep natural distinction to work upon.

Now, there are only two natural sentiments that Utility can appeal to: (1) Self-Interest, and (2) Generosity, or the interests of others.
The deduction of morals from Self-Love is obvious, and no doubt explains much.

An appeal to experience, however, shows its defects.

We praise virtuous actions in remote ages and countries, where our own interests are out of the question.

Even when we have a private interest in some virtuous action, our praise avoids that part of it, and prefers to fasten on what we are not interested in.