According to the Internet Encyclopedia of Philosophy, one philosophical view states that the essential purpose of law in human society is the promotion or achievement of social order. Legal rules comprise a system that is intended to guide human behavior to a desirable end.
Lon Fuller, a philosopher featured in the Internet Encyclopedia of Philosophy, states that legal rules have to be widely known to the public and have to be understandable. In Fuller's view, no legal rules that fail to satisfy these criteria can successfully guide human behavior, because the public has to be able to understand what the rules entail.
Philosophers and theorists of law differ on the genesis and exact nature of law, but most tend to agree that it plays a role as a guiding force of behavior within a society. The Internet Encyclopedia of Philosophy explains, for example, that some see law and morality as intrinsically related or conceptually overlapping, while others see legal rules as those valid, authoritative rules that emerge from a set of social facts regardless of morality or ethics.
According to The Anarchist Library, some proponents of anarchism as a political philosophy do not think that man-made law is necessary in a human society. In this view, social codes that may or may not qualify as laws emerge organically, without the imposition of a social order from above.