Sex is a problem in ethics.
That proposition, that selfishness is sin only when it violates the Decalogue, is farsighted, promotes universal welfare, is cooperative and peaceful, is not divisive and hostile, is born out by history and experience, utilizes human resources better, agrees with Moses, Solon, Aristotle, Cicero, Seneca, Aquinas, Luther, Calvin, Burke, Kant, Lincoln, and other great thinkers. They may have formulated their ethics in different words, but their basic position is restricted to the prohibition of specified evils, that is, to Individualism, properly understood. That constitutes the viscera of morality and of Individualism. A corollary to such a definition of sin is that all else is properly to be left free. Sex and selfishness, neither sinful in itself, are not learned.