Law, in a sense of the term both sufficiently popular and scientific for my purpose, is A RULE OF ACTION. In its generic signification, it is applicable to every kind of action, whether of matter or of mind -- whether intelligent or unintelligent -- whether free or necessary action.

Physical law is a term that represents the order of sequence, in all the changes that occur under the law of necessity, whether in matter or mind. I mean all changes whether of state or action, that do not consist in the states or actions of free will. Physical law is the law of the material universe. It is also the law of mind, so far as its states and changes are involuntary. All mental states or actions, which are not free and sovereign actions of will, must occur under, and be subject to, physical law. They cannot possibly be accounted for, except as they are ascribed to the law of necessity or force.

Moral law is a rule of moral action with sanctions. It is that rule to which moral agents ought to conform all their voluntary actions, and is enforced by sanctions equal to the value of the precept. It is the rule for the government of free and intelligent action, as opposed to necessary and unintelligent action. It is the law of liberty, as opposed to the law of necessity -- of motive and free choice, as opposed to force of every kind. Moral law is primarily a rule for the direction of the action of free will, and strictly of free will only. But secondarily, and less strictly, it is the rule for the regulation of all those actions and states of mind and body, that follow the free actions of will by a law of necessity. Thus, moral law controls involuntary mental states and outward action only by securing conformity of the actions of free will to its precept.

The essential attributes of moral law, are,

1. Subjectivity. It is, and must be, an idea of reason developed in the mind of the subject. It is an idea, or conception, of that state of will, or course of action, which is obligatory upon a moral agent. No one can be a moral agent, or the subject of moral law, unless he has this idea developed; for this idea is identical with the law. It is the law developed or revealed within himself; and thus he becomes "a law to himself," his own reason affirming his obligation to conform to this idea, or law.

2. Objectivity. Moral law may be regarded as a rule of duty, prescribed by the supreme Lawgiver, and external to self. When thus contemplated, it is objective.

3. Liberty, as opposed to necessity. The precept must lie developed in the reason, as a rule of duty -- a law of moral obligation -- a rule of choice, or of ultimate intention, declaring that which a moral agent ought to choose, will, intend. But it does not, must not, can not possess the attribute of necessity in its relations to the actions of free will. It must not, cannot, possess an element or attribute of force, in any such sense as to render conformity of will to its precept unavoidable. This would confound it with physical law.

4. Fitness. It must be the law of nature, that is, its precept must prescribe and require just those actions of the will which are suitable to the nature and relations of moral beings, and nothing more nor less; that is, the intrinsic value of the well-being of God and of the universe being given as the ground, and the nature and relations of moral beings as the condition of the obligation, the reason hereupon necessarily affirms the intrinsic propriety and fitness of choosing this good, and of consecrating the whole being to its promotion. This is what is intended by the law of nature. It is the law or rule of action imposed on us by God, in and by the nature which he has given us.

5. Universality. The conditions and circumstances being the same, it requires, and must require, of all moral agents, the same things, in whatever world they may be found.

6. Impartiality. Moral law is no respecter of persons -- knows no privileged classes. It demands one thing of all, without regard to anything, except the fact that they are moral agents. By this it is not intended that the same course of outward conduct is required of all; but the same state of heart in all -- that all shall have one ultimate intention -- that all shall consecrate themselves to one end -- that all shall entirely conform, in heart and life, to their nature and relations.

7. Practicability. That which the precept demands must be possible to the subject. That which demands a natural impossibility is not, and cannot be, moral law. The true definition of law excludes the supposition that it can, under any circumstances, demand an absolute impossibility. Such a demand could not be in accordance with the nature and relations of moral agents, and therefore practicability must always be an attribute of moral law. To talk of inability to obey moral law is to talk nonsense.

8. Independence. It is an eternal and necessary idea of the divine reason. It is the eternal, self-existent rule of the divine conduct, the law which the intelligence of God prescribes to himself. Moral law, as we shall see hereafter more fully, does not, and cannot originate in the will of God. It eternally existed in the divine reason. It is the idea of that state of will which is obligatory upon God, upon condition of his natural attributes, or, in other words, upon condition of his nature. As a law, it is entirely independent of his will just as his own existence is. It is obligatory also upon every moral agent, entirely independent of the will of God. Their nature and relations being given, and their intelligence being developed, moral law must be obligatory upon them, and it lies not in the option of any being to make it otherwise. Their nature and relations being given, to pursue a course of conduct suited to their nature and relations, is necessarily and self-evidently obligatory, independent of the will of any being.

9. Immutability. Moral law can never change, or be changed. It always requires of every moral agent a state of heart, and course of conduct, precisely suited to his nature and relations. Whatever his nature is, his capacity and relations are, entire conformity to just that nature, those capacities and relations, so far as he is able to understand them, is required at every moment, and nothing more nor less. If capacity is enlarged, the subject is not thereby rendered capable of works of supererogation -- of doing more than the law demands; for the law still, as always, requires the full consecration of his whole being to the public interests. If by any means whatever, his ability is abridged, moral law, always and necessarily consistent with itself, still requires that what is left -- nothing more or less -- shall be consecrated to the same end as before. Whatever demands more or less than entire, universal, and constant conformity of heart and life, to the nature, capacity and relations of moral agents, be they what they may, is not, and cannot be moral law. If therefore, the capacity is by any means abridged, the subject does not thereby become incapable of rendering full obedience; for the law still demands and urges, that the heart and life shall be fully conformed to the present, existing nature, capacity, and relations. Anything that requires more or less than this, cannot be moral law. Moral law invariably holds one language. It never changes its requirement. "Thou shalt love," or be perfectly benevolent, is its uniform and its only demand. This demand it never varies, and never can vary. It is as immutable as God is, and for the same reason. To talk of letting down, or altering moral law, is to talk absurdly. The thing is naturally impossible. No being has the right or the power to do so. The supposition overlooks the very nature of moral law. Moral law is not a statute, an enactment, that has its origin or its foundation in the will of any being. It is the law of nature, the law which the nature or constitution of every moral agent imposes on himself and which God imposes upon us because it is entirely suited to our nature and relations, and is therefore naturally obligatory upon us. It is the unalterable demand of the reason, that the whole being, whatever there is of it at any time, shall be entirely consecrated to the highest good of universal being, and for this reason God requires this of us, with all the weight of his authority.

10. Unity. Moral law proposes but one ultimate end of pursuit to God, and to all moral agents. All its requisitions, in their spirit, are summed up and expressed in one word, love or benevolence. This I only announce here. It will more fully appear hereafter. Moral law is a pure and simple idea of the reason. It is the idea of perfect, universal, and constant consecration of the whole being to the highest good of being. Just this is, and nothing more nor less can be, moral law; for just this, and nothing more nor less, is a state of heart and a course of life exactly suited to the nature and relations of moral agents, which is the only true definition of moral law.

11. Expediency. That which is upon the whole most wise is expedient. That which is upon the whole expedient is demanded by moral law. True expediency and the spirit of moral law are always identical. Expediency may be inconsistent with the letter, but never with the spirit of moral law. Law in the form of commandment is a revelation or declaration of that course which is expedient. It is expediency revealed, as in the case of the decalogue, and the same is true of every precept of the Bible, it reveals to us what is expedient. A revealed law or commandment is never to be set aside by our views of expediency. We may know with certainty that what is required is expedient. The command is the expressed judgment of God in the case, and reveals with unerring certainty the true path of expediency. When Paul says, "All things are lawful unto me, but all things are not expedient," we must not understand him as meaning that all things in the absolute sense were lawful to him, or that anything that was not expedient was lawful to him. But he doubtless intended, that many things were inexpedient that are not expressly prohibited by the letter of the law, -- that the spirit of the law prohibited many things not expressly forbidden by the letter. It should never be forgotten that that which is plainly demanded by the highest good of the universe is law. It is expedient. It is wise. The true spirit of the moral law does and must demand it. So, on the other hand, whatever is plainly inconsistent with the highest good of the universe is illegal, unwise, inexpedient, and must be prohibited by the spirit of moral law. But let the thought be repeated, that the Bible precepts always reveal that which is truly expedient, and in no case are we at liberty to set aside the spirit of any commandment upon the supposition that expediency requires it. Some have denounced the doctrine of expediency altogether, as at all times inconsistent with the law of right. These philosophers proceed upon the assumption that the law of right and the law of benevolence are not identical but inconsistent with each other. This is a common but fundamental mistake, which leads me to remark that -- Law proposes the highest good of universal being as its end, and requires all moral agents to consecrate themselves to the promotion of this end. Consequently, expediency must be one of its attributes. That which is upon the whole in the highest degree useful to the universe must be demanded by moral law. Moral law must, from its own nature, require just that course of willing and acting that is upon the whole in the highest degree promotive of the public good, -- in other words, that which is upon the whole in the highest degree useful, and therefore expedient. It has been strangely and absurdly maintained that right would be obligatory if it necessarily tended to and resulted in universal and perfect misery. Than which a more nonsensical affirmation was never made. The affirmation assumes that the law of right and of good-will are not only distinct, but may be antagonistic. It also assumes that that can be law that is not suited to the nature and relations of moral agents. Certainly it will not be pretended that that course of willing and acting that necessarily tends to, and results in, universal misery, can be consistent with the nature and relations of moral agents. Nothing is or can be suited to their nature and relations, that is not upon the whole promotive of their highest well-being. Expediency and right are always and necessarily at one. They can never be inconsistent. That which is upon the whole most expedient is right, and that which is right is upon the whole expedient.

12. Exclusiveness. Moral law is the only possible rule of moral obligation. A distinction is usually made between moral, ceremonial, civil and positive laws. This distinction is in some respects convenient, but is liable to mislead, and to create an impression that something can be obligatory, in other words can be law, that has not the attributes of moral law. Nothing can be law, in any proper sense of the term, that is not and would not be universally obligatory upon moral agents under the same circumstances. It is law because, and only because, under all the circumstances of the case, the course prescribed is fit, proper, suitable, to their natures, relations, and circumstances. There can be no other rule of action for moral agents but moral law, or the law of benevolence. Every other rule is absolutely excluded by the very nature of moral law. Surely there can be no law that is or can be obligatory upon moral agents but one suited to, and founded in their nature, relations, and circumstances. This is and must be the law of love or benevolence. This is the law of right, and nothing else is or can be. Every thing else that claims to be law, and to impose obligation upon moral agents, must be an imposition and "a thing of nought."