on the other, to the action which he ought to do. Those two correlates are essential to every moral obligation; take away either, and it has no existence. So that, if we seek the place of moral obligation among the categories, it belongs to the category of relation.

There are many relations of things, of which we have the most distinct conception, without being able to define them logically. Equality and proportion are relations between quantities, which every man understands, but no man can define.

Moral obligation is a relation of its own kind, which every man understands, but is perhaps too simple to admit of logical definition. Like all other relations, it may be changed or annihilated by a change in any of the two related things, I mean the agent or the action.

Perhaps it may not be improper to point out briefly the circumstances, both in the action and in the agent, which are necessary to constitute moral obligation. The universal agreement of men in these, shows that they have one and the same notion of it.

With regard to the action, it must be a voluntary action, or prestation of the person obliged, and not of another. There can be no moral obligation upon a man to be six feet high. Nor can I be under a moral obligation that another person should do such a thing. His actions must be imputed to himself, and mine only to me, either for praise or blame.

I need hardly mention, that a person can be under a moral obligation, only to things within the sphere of his natural power. [Note X.]

As to the party obliged it is evident, there can be no moral obligation upon an inanimate thing. To speak of moral obligation upon a stone or a tree is ridiculous, because it contradicts every man's notion of moral obligation.

The person obliged must have understanding and will, and some degree of active power. He must not

only have the natural faculty of understanding, but the means of knowing his obligation. An invincible ignorance of this destroys all moral obligation.

The opinion of the agent in doing the action gives it its moral denomination. If he does a materially good action, without any belief of its being good, but from some other principle, it is no good action in him. And if he does it with the belief of its being ill, it is ill in him.

Thus, if a man should give to his neighbour a potion which he really believes will poison him, but which, in the event, proves salutary, and does much good; in moral estimation, he is a poisoner, and not a benefactor.

These qualifications of the action and of the agent, in moral obligation, are self-evident; and the agreement of all men in them shows, that all men have the same notion, and a distinct notion of moral obligation.

CHAP. VI.

OF THE SENSE OF DUTY.

We are next to consider, how we learn to judge and determine, that this is right, and that is wrong.

The abstract notion of moral good and ill would be of no use to direct our life, if we had not the power of applying it to particular actions, and determining what is morally good, and what is morally ill.

Some philosophers, with whom I agree, ascribe this to an original power or faculty in man, which they call the moral sense, the moral faculty, conscience. Others think, that our moral sentiments may be accounted for without supposing any original sense or faculty appropriated to that purpose, and go into very different systems to account for them.

I am not, at present, to take any notice of those systems, because the opinion first mentioned seems to me to be the truth, to wit, that, by an original power of the mind, when we come to years of understanding and reflection, we not only have the notions of right and wrong in conduct, but perceive certain things to be right, and others to be wrong.

The name of the moral sense, though more frequently given to conscience since lord Shaftesbury and Dr. Hutcheson wrote, is not new. The sensus recti et honesti is a phrase not unfrequent among the ancients, neither is the sense of duty among us.

senses.

It has got this name of sense, no doubt, from some analogy which it is conceived to bear to the external And if we have just notions of the office of the external senses, the analogy is very evident, and I see no reason to take offence, as some have done, at the name of the moral sense.

The offence taken at this name seems to be owing to this, that philosophers have degraded the senses too

much, and deprived them of the most important part of their office.

We are taught, that by the senses, we have only certain ideas which we could not have otherwise. They are represented as powers by which we have sensations and ideas, not as powers by which we judge.

This notion of the senses I take to be very lame, and to contradict what nature and accurate reflection teach concerning them.

A man who has totally lost the sense of seeing, may retain very distinct notions of the various colours; but he cannot judge of colours, because he has lost the sense by which alone he could judge. By my eyes I not only have the ideas of a square and a circle, but I perceive this surface to be a square, that to be a circle.

By my ear, I not only have the idea of sounds, loud and soft, acute and grave, but I immediately perceive and judge this sound to be loud, that to be soft, this to be acute, that to be grave. Two or more synchronous sounds I perceive to be concordant, others to be discordant.

These are judgments of the senses. They have always been called and accounted such, by those whose minds are not tinctured by philosophical theories. They are the immediate testimony of nature by our senses; and we are so constituted by nature, that we must receive their testimony, for no other reason but because it is given by our senses.

In vain do skeptics endeavour to overturn this evidence by metaphysical reasoning. Though we should not be able to answer their arguments, we believe our senses still, and rest our most important concerns upon their testimony.

If this be a just notion of our external senses, as I conceive it is, our moral faculty may, I think, without impropriety, be called the moral sense.

In its dignity it is, without doubt, far superior to every other power of the mind; but there is this analogy be

tween it and the external senses, that, as by them we have not only the original conceptions of the various qualities of bodies, but the original judgments that this body has such a quality, that such another; so by our moral faculty, we have both the original conceptions of right and wrong in conduct, of merit and demerit, and the original judgments that this conduct is right, that is wrong; that this character has worth, that, demerit.

The testimony of our moral faculty, like that of the external senses, is the testimony of nature, and we have the same reason to rely upon it.

The truths immediately testified by the external senses are the first principles from which we reason, with regard to the material world, and from which all our knowledge of it is deduced.

The truths immediately testified by our moral faculty, are the first principles of all moral reasoning, from which all our knowledge of our duty must be deduced. [Note Y.]1

By moral reasoning, I understand all reasoning that is brought to prove that such conduct is right, and deserving of moral approbation, or that it is wrong, or that it is indifferent, and, in itself, neither morally good nor ill.

I think all we can properly call moral judgments are reducible to one or other of these, as all human actions, considered in a moral view, are either good, or bad, or indifferent.

I know the term moral reasoning is often used by good writers in a more extensive sense; but as the reasoning I now speak of is of a peculiar kind, distinct from all others, and therefore ought to have a distinct name, I take the liberty to limit the name of moral reasoning to this kind.