What is Law Of Nature?

Legal Definition
The law of nature is that which God, the sovereign of the universe, has prescribed to all men, not by any formal promulgation, but by the internal dictate of reason alone. It is discovered by a just consideration of the agreeableness or disagreeableness of human actions to the nature of man; and it comprehends all the duties which we owe either to the Supreme Being, to ourselves, or to our neighbors; as reverence to God, self-defence, temperance, honor to our parents, benevolence to all, a strict adherence to our engagements, gratitude, and the like. Erskines Pr. of L. of Scot. B. 1, t. 1, s. 1. See Ayl. Pand. tit. 2, p. 5; Cicer. de Leg. lib. 1.

2. The primitive laws of nature may be reduced to six, namely: 1. Comparative sagacity, or reason. 2. Self-love. 3. The attraction of the sexes to each other. 4. The tendemess of parents towards their children. 5. The religious sentiment. 6. Sociability.

3. - 1. When man is properly organized, he is able to discover moral good from moral evil; and the study of man proves that man is not only an intelligent, but a free being, and he is therefore responsible for his actions. The judgment we form of our good actions, produces happiness; on the contrary the judgment we form of our bad actions produces unhappiness.

4. - 2. Every animated being is impelled by nature to his own preservation, to defend his life and body from injuries, to shun what may be hurtful, and to provide all things requisite to his existence. Hence the duty to watch over his own preservation. Suicide and duelling are therefore contrary to this law; and a man cannot mutilate himself, nor renounce his liberty.

5. - 3. The attraction of the sexes has been provided for the preservation of the human race, and this law condemns celibacy. The end of marriage proves that polygamy, (q. v.) and polyendry, (q. v.) are contrary to the law of nature. Hence it follows that the husband and wife have a mutual and exclusive right over each other.

6. - 4. Man from his birth is wholly unable to provide for the least of his necessities; but the love of his parents supplies for this weakness. This is one of the most powerful laws of nature. The principal duties it imposes on the parents, are to bestow on the child all the care its weakness requires, to provide for its necessary food and clothing, to instruct it, to provide for its wants, and to use coercive means for its good, when requisite.

7. - 5. The religious sentiment which leads us naturally towards the Supreme Being, is one of the attributes which belong to humanity alone; and its importance gives it the rank of the moral law of nature. From this sentiment arise all the sects and different forms of worship among men.

8. - 6. The need which man feels to live in society, is one of the primitive laws of nature, whence flow our duties and rights; and the existence of society depends upon the condition that the rights of all shall be respected. On this law are based the assistance, succors and good offices which men owe to each other, they being unable to provide each every thing for himself.
-- Bouviers Law Dictionary
Legal Definition
“Those fit and just rules of conduct which the Creator has prescribed to man as a dependent and social being, and which are to be ascertained from the deductions of right reason, though they may be more precisely known and more explicitly declared by divine revelation.” See 4 Johns. Ch. (N. Y) 343.
-- Ballentine's Law Dictionary
Legal Definition
-- Black's Law Dictionary