Further, unless the human soul be an exception, God governs all things by laws adopted to their proper nature. The laws which govern the material world are sketched in the books on natural science; such are gravitation, affinity, mathematical motion. Those laws by which the irrational animal creations are controlled are usually called instincts. Their operation and design are sketched, to some extent, in treatises upon the instincts of animals. Such is the law which leads the beaver to build its dam, and all other animals to pursue some particular habits instead of others. All beavers, from the first one created to the present time, have been instinctively led to build a dam in the same manner, and so their instinct will lead them to build till the end of time. The law which drives them to the act is as necessitating as the law which causes the smoke to rise upwards. Nothing in the universe of God, animate or inanimate, is left without the government of appropriate law, unless that thing being the noblest creature of God: the human spirit. To suppose, therefore, that the human soul is thus left unguided by a revealed rule of conduct, is to suppose that God cares for the less and not for the greater: to suppose that He would constitute the moral powers of the soul so that a law was necessary for their guidance, and then revealed none: to suppose, especially in the case of the Israelites, that he would prepare a people to receive, and obey with a proper spirit, this necessary rule of duty, and yet give no rule. But to suppose these things would be absurd; it follows, therefore, that God would reveal to the Israelites a law for the regulation of their conduct in morals and religion. But physical law or necessitating instinct would not be adapted in its nature to the government of a rational and moral being. The obligation of either to the soul would destroy its free agency. God has made man intelligent, and thereby adapted his nature to a rule which he understands. Man has a will and a conscience; but he must understand the rule in order to will obedience, and he must believe the sanction by which the law is maintained before he can feel the obligation upon his conscience. A law, therefore, adapted to man's nature, must be addressed to the understanding, sanctioned by suitable authority, and enforced by adequate penalties. In accordance with these legitimate deductions, God gave the Israelites a rule of life--the moral law--succinctly comprehended in the Ten Commandments. And as affectionate obedience is the only proper obedience he coupled the facts which were fitted to produce affection with the command to obey; saying, "I am the Lord thy God, which brought thee out of the land of Egypt, and from the house of bondage." Therefore, if ye love the Lord ye shall surely keep His commandments.