Law of Moses

In the Guide 3: 26–49 Maimonides discusses the reasons of the commandments. Maimonides considers a distinction made by Mutazilite philosophers, Saadiah among them. These philosophers had divided divine law into two categories: rational commandments, such as the prohibitions against murder and theft, which the human mind can discover without revelation, and revealed commandments, such as prayer and the observance of holidays, which are neutral from the point of view of reason and can be known only through revelation. Maimonides understands this position as implying that the revelational commandments come from God's will rather than His reason. Against this view, Maimonides argues that all divine commandments are the product of God's wisdom, though he adds that some are easily intelligible (mishpatim), and others intelligible only with difficulty (hukkim). However, Maimonides adds that particular commandments have no rational principle behind them and are commandments only because God willed them.

Maimonides postulates two purposes of the Law: the well-being of the soul (intellect) and the well-being of the body, by which he means man's moral well-being. The former is acquired through true beliefs, the latter, through political and personal morality. The beliefs which a man must accept are graded according to his intellectual ability. There are also true beliefs, such as the existence of God, His unity, and His incorporeality, which everyone must accept regardless of intellectual ability, and there are beliefs, such as that God gets angry at those who disobey Him, which have primarily a political function and are considered necessary beliefs. Ordinary men will accept the Law only if they are promised rewards or threatened with punishment, and it is the function of the necessary beliefs to provide such motivation. They are unnecessary for the philosopher, who obeys the Law because it is the right thing to do regardless of consequences.

Although reasons for general moral laws can readily be found, it is more difficult to explain the numerous ritual laws found in the Bible. Maimonides explains many of them as reactions to pagan practices, and he makes use of his extensive familiarity with such books as the Nabatean Agriculture, which describe such practices. Thus, for example, he explains the Biblical prohibition against wearing garments made of wool and linen combined as a reaction to a pagan practice requiring priests to wear such garments. Maimonides also considers certain commandments as concessions to historical situations, such as those dealing with sacrifice. Worship without animal sacrifices is preferred, but it would have been unrealistic to require the Israelites leaving Egypt to give up sacrifices altogether. Hence the Bible commanded sacrifices, restricting, however, the times and places for them and permitting only priests to offer them. We should not infer from this, however, that Maimonides believed in a progressive development of Jewish law, in fact, he codifies all of Rabbinic law in his Mishneh Torah. The Guide concludes with a supplementary section on the perfect worship of God and man's perfection.