And human beings cannot do without a law to live by in this world, for they must act to secure benefit and act to ward off harm. The revealed law distinguishes between actions that benefit them and actions that harm them. It is Allah’s justice within His creation and His light among His servants. Human beings therefore cannot live without a law by which they distinguish what they should do from what they should refrain from doing.

What is meant by law is not merely justice between people in their dealings. Even a person living alone must do some things and refrain from others, for a human being is one who continually intends and acts. As the Prophet, may Allah bless him and grant him peace, said:

“The names that most truthfully describe their bearers are Hārith and Hammām.”

This is what is meant by describing a human being as acting through volition. When someone has a will, he acts upon it, and he must know whether what he wants is beneficial or harmful to him, and whether it makes him better or corrupts him.

People know some of this through their innate disposition, just as they know that eating and drinking benefit them, and just as their innate disposition gives them self-evident knowledge. Others know it through inference, as with the conclusions to which their reason guides them. Some of it, however, they know only through the messengers’ teaching, explanation, and guidance.

It is in this connection that people have debated whether the goodness and badness of actions can be known by reason, or whether actions have no goodness or badness that can be known by reason. This has been discussed at length elsewhere, and we have explained the confusion that has arisen concerning this question. They agree that whether an act is congenial or repugnant to the one who performs it can be known by reason, which means