We can never get people to act morally by providing reasons of self-interest, because if they accept what we say and act on the reasons given, they will only be acting self-interested, not morally. By refuting this claim, it would be stated that the substance of the action, what is actually done, is more important than the motive. People might give money to help those in extreme poverty because their friends will think better of them if they do, or they might give the same amount because they think it is their duty. Those helped by the gift will benefit to the same extent either way. This is true but crude. It can be made more sophisticated if it is combined with an appropriate account of the nature and function of ethics. Ethics is a social practice that has evolved among beings living in social groups, and it promotes ways of living that are in the interests of individuals living in groups. Ethical judgments can do this by praising and encouraging actions in accordance with these values.