299. Primary and secondary laws of nature are also explained as follows: (a) a primary law is one that expresses the principal purpose of a natural inclination (e.g., social good, that is, the begetting and rearing of children, is the primary law of the married state); (b) the secondary law is one that expresses a less important purpose of a natural inclination. For example, individual good (i.e., companionship, mutual assistance, the practice of virtue and freedom from temptation) is the secondary purpose to be promoted in the married state. 300. Precepts of the Natural Law may be divided also on account of the different relations they have to one another or to our knowledge. (a) According to the priority they have among themselves, the laws of nature are divided into the first principle and the secondary principles. The first principle, which is general, which depends on no other, and which is the root of all the others, is: “Good must be done, evil omitted.” The secondary principles are particular, and they apply this general principle to the natural inclinations of man mentioned above, which reason indicates as ends of action--i.e., as goods to be sought. (b) According to the priority they have with respect to our knowledge of them, the laws of nature are divided, first, into axiomatic precepts, which are evident and are granted by all (e.g., that good is to be done, that one should follow reason, that one should not do to others what one does not wish done to oneself etc.), and, secondly, into inferred precepts (e.g., that one should not steal from others, as one does not wish others to steal from oneself). 301. The inferred precepts are also of two kinds, namely, general and particular. (a) The general precepts are those that are deduced immediately from the axioms as universal conclusions (e.g., the commandments of the Decalogue, the principle that one should return what one borrowed). (b) The particular precepts are those that are deduced only remotely from the axioms as conclusions about cases in which many particular conditions and circumstances are involved (e.g., many conclusions about contracts, the conclusion that a loan is to be paid in some particular way, at this particular time, etc.).