He enounces this all-comprehensive proposition: 'The same necessary and eternal different Relations that different Things bear one to another, and the same consequent Fitness or Unfitness of the application of different things or different relations one to another, with regard to which the will of God always and necessarily does determine itself to choose to act only what is agreeable to Justice, Equity, Goodness, and Truth, in order to the welfare of the whole universe—ought likewise constantly to determine the Wills of all subordinate rational beings, to govern all their actions by the same rules, for the good of the public, in their respective stations. That is, these eternal and necessary differences of things make it fit and reasonable for creatures so to act; they cause it to be their duty, or lay an obligation on them so to do; even separate from the consideration of these Rules being the positive Will or Command of God, and also antecedent to any respect or regard, expectation or apprehension of any particular private and personal Advantage or Disadvantage, Reward or Punishment, either present or future, annexed either by natural consequence, or by positive appointment, to the practising or neglecting of these rules. In the explication of this, nearly his whole system is contained.

His first concern is to impress the fact that there are necessary and eternal differences of ail things, and implied or consequent relations (proportions or disproportions) existing amongst them; and to bring under this general head the special case of differences of Persons (e.g., God and Man, Man and Fellow-man), for the sake of the implication that to different persons there belong peculiar Fitnesses and Unfitnesses of circumstances; or, which is the same thing, that there arises necessarily amongst them a suitableness or unsuitableness of certain manners of Behaviour. The counter-proposition that he contends against is, that the relations among persons depend upon positive constitution of some kind, instead of being founded unchangeably in the nature and reason of things.

Next he shows how, in the rational or intellectual recognition of naturally existent relations amongst things (he always means persons chiefly), there is contained an obligation. When God, in his Omniscience and absolute freedom from error, is found determining his Will always according to this eternal reason of things, it is very unreasonable and blameworthy in the intelligent creatures whom he has made so far like himself, not to govern their actions by the same eternal rule of Reason, but to suffer themselves to depart from it through negligent misunderstanding or wilful passion. Herein lies obligation: a man ought to act according to the Law of Reason, because he can as little refrain from assenting to the reasonableness and fitness of guiding his actions by it, as refuse his assent to a geometrical demonstration when he understands the terms. The original obligation of all is the eternal Reason of Things; the sanction of Rewards and Punishments (though 'truly the most effectual means of keeping creatures in their duty') is only a secondary and additional obligation. Proof of his position he finds in men's judgment of their own actions, better still in their judgments of others' actions, best of all in their judgment of injuries inflicted on themselves. Nor does any objection hold from the ignorance of savages in matters of morality: they are equally ignorant of the plainest mathematical truths; the need of instruction does not take away the necessary difference of moral Good and Evil, any more than it takes away the necessary proportions of numbers. He, then, instead of deducing all our several duties as he might, contents himself with mentioning the three great branches of them, (a) Duties in respect of God, consisting of sentiments and acts (Veneration, Love, Worship, &c.) called forth by the consideration of his attributes, and having a character of Fitness far beyond any that is visible in applying equal geometrical figures to one another, (b) Duties in respect of our Fellow-creatures: (1) Justice and Equity, the doing as we would be done by. Iniquity is the very same in Action, as Falsity or Contradiction in Theory; what makes the one absurd makes the other unreasonable; 'it would be impossible for men not to be as much (!) ashamed of doing Iniquity, as they are of believing Contradictions;' (2) Universal Love or Benevolence, the promoting the welfare or happiness of all, which is obligatory on various grounds: the Good being the fit and reasonable, the greatest Good is the most fit and reasonable; by this God's action is determined, and so ought ours; no Duty affords a more ample pleasure; besides having a 'certain natural affection' for those most closely connected with us, we desire to multiply affinities, which means to found society, for the sake of the more comfortable life that mutual good offices bring. [This is a very confused deduction of an obligation.'] (c) Duties in respect to our Selves, viz., self-preservation, temperance, contentment, &c.; for not being authors of our being, we have no just power or authority to take it away directly, or, by abuse of our faculties, indirectly.

After expatiating in a rhetorical strain on the eternal, universal, and absolutely unchangeable character of the law of Nature or Right Reason, he specifies the sense wherein the eternal moral obligations are independent of the will of God himself; it comes to this, that, although God makes all things and the relations between them, nothing is holy and good because he commands it, but he commands it because it is holy and good. Finally, he expounds the relation of Reward and Punishment to the law of Nature; the obligation of it is before and distinct from these; but, while full of admiration for the Stoical idea of the self-sufficiency of virtue, he is constrained to add that 'men never will generally, and indeed 'tis not very reasonably to be expected they should, part with all the comforts of life, and even life itself, without any expectation of a future recompense.' The 'manifold absurdities' of Hobbes being first exposed, he accordingly returns, in pursuance of the theological argument of his Lectures, to show that the eternal moral obligations, founded on the natural differences of things, are at the same time the express will and command of God to all rational creatures, and must necessarily and certainly be attended with Rewards and Punishments in a future state.

The summary of Clarke's views might stand thus:—

I.—The STANDARD is a certain Fitness of action between persons, implicated in their nature as much as any fixed proportions between numbers or other relation among things. Except in such an expression as this, moral good admits of no kind of external reference.

II.—There is very little Psychology involved. The Faculty is the Reason; its action a case of mere intellectual apprehension. The element of Feeling is nearly excluded. Disinterested sentiment is so minor a point as to call forth only the passing allusion to 'a certain natural affection.'

III.—Happiness is not considered except in a vague reference to good public and private as involved with Fit and Unfit action.

IV.—His account of Duties is remarkable only for the consistency of his attempt to find parallels for each amongst intellectual relations. The climax intended in the assimilation of Injustice to Contradictions is a very anti-climax; if people were only 'as much' ashamed of doing injustice as of believing contradictions, the moral order of the world would be poorly provided for.

V.—The relation of Ethics to Politics is hardly touched. Society is born of the desire to multiply affinities through mutual interchange of good offices.