The way we think of human nature has a powerful impact on what we think is right and wrong and what we think is a happy life. For example, if we believe that human nature is basically selfless, as Marx did, then we'll probably favor some form of socialism, in which there is no profit incentive to produce high-quality software. But we know that socialism doesn't work, because human nature is not entirely selfless. Marx grasped only one side of human nature, the social side; he failed to see the individualistic side. The English philosopher Thomas Hobbes (1588--1679) fell into the opposite error. He saw human nature as basically individualistic and selfish. According to Hobbes, civil society is a convenient arrangement which we've invented to prevent ourselves from killing each other off, but it's not natural for human beings to live in society or to restrain their egoistic impulses. It's natural for each individual to attack and plunder his neighbors, to take software and other goods from them by cunning or by force. It's hard to see how anyone, on such a conception of human nature, could be happy living under the restraints of civil society. Fortunately, that conception is wrong.
Norm's ethical theory, which makes a strong connection between moral values, human happiness, and human nature, is called "ethical naturalism" or sometimes "natural law" theory. Its roots are in the philosophies of Plato and Aristotle.