On the basis of a homily dating from the third century CE, there are said to be 613 precepts, 365 negative (“do not do this”) and 248 positive (“do this”), but this numbering of the precepts did not really come into prominence until the medieval period. The distinction, however, between positive and negative precepts is found throughout Rabbinic literature. In that literature the term mitzvah is used for a negative precept as well as a positive, but mitzvah is more usually reserved for a positive precept, while the more usual term to denote a negative precept is averah (“transgression”); as when, for instance, it is said that a stolen palm-branch must not be used on the festival of Tabernacles [Sukkot] because it is an averah.
A further classification of the precepts is that of “between man and God” and “between man and his neighbor,” that is, religious and social obligations, although both are seen ultimately as having their sanction in a divine command. Another classification distinguished positive precepts that depend for their performance on time (e.g. the precept of tefillin which is only obligatory during daytime) and precepts that are binding whatever the time in which they are carried out (love of the neighbor, for instance). Women are exempt from carrying out the former.
Still another classification is between light and heavy precepts, that is, those that can easily be carried out and those that require much effort and are costly to carry out. In Ethics of the Fathers (2:1) the advice is given to treat light precepts as seriously as one treats heavy precepts, “since you do not know the reward for the precepts” and the performance of a light precept may win a greater reward from heaven than the performance of a heavy precept. Not that it is ideal to carry out the precepts in anticipation of reward for so doing. Against such a calculating attitude stands the rabbinic doctrine of lishmah (“or its own sake”), of doing God’s will without any ulterior motivation. For all that, it is advised to carry out the precepts even if the motivation is not entirely pure (shelo lishmah), since persistence in carrying out the precepts will eventually lead to performance out of pure motivation. The obligation to keep the precepts begins when a boy reaches the age of 13 and a girl the age of 12, hence the terms Bar Mitzvah and Bat Mitzvah.
The rabbinic ideal is to carry out the precepts joyfully. It is generally assumed that Jews have simchah shel mitzvah, “joy in the mitzvah,” and that even sinners in Israel are as full of mitzvot as a pomegranate is full of seeds (Hagigah 27a). The Jerusalem Talmud uses the term mitzvah to denote especially a deed of charity, the mitzvah par excellence. In Yiddish, a mitzvah often means any good deed, just as an averah is anything bad or wasteful.
For the talmudic rabbis, the fact that God commanded the positive and negative precepts is sufficient reason for the Jew to keep them. But the medieval philosophers seek to provide reasons for those precepts such as the dietary laws for which no reason is stated in the Torah. Maimonides devotes a large section of the third part of his Guide of the Perplexed to reasons for those precepts which seem on the surface to be irrational. Some thinkers were opposed to the whole attempt to discover reasons for the precepts, arguing that, apart from the rabbinic stress on pure obedience, if reasons are suggested they could easily lead to neglect where it is assumed the reasons do not apply.
If, for example, the dietary laws are explained on hygienic grounds, this could lead to Jews saying that the laws need not be kept where improved methods of food production and the advance of medicine have made the risk to health more remote than it was in ancient times. On the other hand, those thinkers who did seek reasons believed that unless it can be shown that the observance of the mitzvot is reasonable, Gentiles will taunt Jews as owing allegiance to an irrational faith in which God tends to be seen as a tyrannical ruler imposing arbitrary laws on His subjects.
In the Kabbalah, observance of the precepts has a cosmic effect, every detail of the precepts having its correspondence in the upper worlds, assisting the harmony of the sefirot [divine emanations] so that the divine grace can flow unimpeded throughout creation. Many modern Jews are far less bothered about the reasons for the precepts or, for that matter, about the question of the origin of the precepts as suggested in biblical scholarship. What matters for such Jews is the opportunity the precepts afford for worshipping God.
Excerpted with permission from The Jewish Religion: A Companion, Oxford University Press.
Pronounced: TALL-mud, Origin: Hebrew, the set of teachings and commentaries on the Torah that form the basis for Jewish law. Comprised of the Mishnah and the Gemara, it contains the opinions of thousands of rabbis from different periods in Jewish history.