No union can be more constant and certain, than that of some actions with some motives and characters; and if in other cases the union is uncertain, it is no more than what happens in the operations of body, nor can we conclude any thing from the one irregularity, which will not follow equally from the other.

It is commonly allowed that mad-men have no liberty. But were we to judge by their actions, these have less regularity and constancy than the actions of wise-men, and consequently are farther removed from necessity. Our way of thinking in this particular is, therefore, absolutely inconsistent; but is a natural consequence of these confused ideas and undefined terms, which we so commonly make use of in our reasonings, especially on the present subject.

We must now shew, that as the union betwixt motives and actions has the same constancy, as that in any natural operations, so its influence on the understanding is also the same, in determining us to infer the existence of one from that of another. If this shall appear, there is no known circumstance, that enters into the connexion and production of the actions of matter, that is not to be found in all the operations of the mind; and consequently we cannot, without a manifest absurdity, attribute necessity to the one, and refuse into the other.

There is no philosopher, whose judgment is so riveted to this fantastical system of liberty, as not to acknowledge the force of moral evidence, and both in speculation and practice proceed upon it, as upon a reasonable foundation. Now moral evidence is nothing but a conclusion concerning the actions of men, derived from the consideration of their motives, temper and situation. Thus when we see certain characters or figures described upon paper, we infer that the person, who produced them, would affirm such facts, the death of Caesar, the success of Augustus, the cruelty of Nero; and remembering many other concurrent testimonies we conclude, that those facts were once really existant, and that so many men, without any interest, would never conspire to deceive us; especially since they must, in the attempt, expose themselves to the derision of all their contemporaries, when these facts were asserted to be recent and universally known. The same kind of reasoning runs through politics, war, commerce, economy, and indeed mixes itself so entirely in human life, that it is impossible to act or subsist a moment without having recourse to it. A prince, who imposes a tax upon his subjects, expects their compliance.

A general, who conducts an army, makes account of a certain degree of courage. A merchant looks for fidelity and skill in his factor or super-cargo. A man, who gives orders for his dinner, doubts not of the obedience of his servants. In short, as nothing more nearly interests us than our own actions and those of others, the greatest part of our reasonings is employed in judgments concerning them. Now I assert, that whoever reasons after this manner, does ipso facto believe the actions of the will to arise from necessity, and that he knows not what he means, when he denies it.

All those objects, of which we call the one cause and the other effect, considered in themselves, are as distinct and separate from each other, as any two things in nature, nor can we ever, by the most accurate survey of them, infer the existence of the one from that of the other. It is only from experience and the observation of their constant union, that we are able to form this inference; and even after all, the inference is nothing but the effects of custom on the imagination. We must not here be content with saying, that the idea of cause and effect arises from objects constantly united; but must affirm, that it is the very same with the idea of those objects, and that the necessary connexion is not discovered by a conclusion of the understanding, but is merely a perception of the mind. Wherever, therefore, we observe the same union, and wherever the union operates in the same manner upon the belief and opinion, we have the idea of causes and necessity, though perhaps we may avoid those expressions. Motion in one body in all past instances, that have fallen under our observation, is followed upon impulse by motion in another.

It is impossible for the mind to penetrate farther. From this constant union it forms the idea of cause and effect, and by its influence feels the necessity. As there is the same constancy, and the same influence in what we call moral evidence, I ask no more. What remains can only be a dispute of words.

And indeed, when we consider how aptly natural and moral evidence cement together, and form only one chain of argument betwixt them, we shall make no scruple to allow, that they are of the same nature, and derived from the same principles. A prisoner, who has neither money nor interest, discovers the impossibility of his escape, as well from the obstinacy of the goaler, as from the walls and bars with which he is surrounded; and in all attempts for his freedom chuses rather to work upon the stone and iron of the one, than upon the inflexible nature of the other. The same prisoner, when conducted to the scaffold, foresees his death as certainly from the constancy and fidelity of his guards as from the operation of the ax or wheel. His mind runs along a certain train of ideas: The refusal of the soldiers to consent to his escape, the action of the executioner; the separation of the head and body; bleeding, convulsive motions, and death. Here is a connected chain of natural causes and voluntary actions; but the mind feels no difference betwixt them in passing from one link to another; nor is less certain of the future event than if it were connected with the present impressions of the memory and senses by a train of causes cemented together by what we are pleased to call a physical necessity.

The same experienced union has the same effect on the mind, whether the united objects be motives, volitions and actions; or figure and motion. We may change the names of things; but their nature and their operation on the understanding never change.

I dare be positive no one will ever endeavour to refute these reasonings otherwise than by altering my definitions, and assigning a different meaning to the terms of cause, and effect, and necessity, and liberty, and chance. According to my definitions, necessity makes an essential part of causation; and consequently liberty, by removing necessity, removes also causes, and is the very same thing with chance. As chance is commonly thought to imply a contradiction, and is at least directly contrary to experience, there are always the same arguments against liberty or free-will. If any one alters the definitions, I cannot pretend to argue with him, until I know the meaning he assigns to these terms.

I believe we may assign the three following reasons for the prevalance of the doctrine of liberty, however absurd it may be in one sense, and unintelligible in any other. First, After we have performed any action; though we confess we were influenced by particular views and motives; it is difficult for us to persuade ourselves we were governed by necessity, and that it was utterly impossible for us to have acted otherwise; the idea of necessity seeming to imply something of force, and violence, and constraint, of which we are not sensible. Few are capable of distinguishing betwixt the liberty of spontaniety, as it is called in the schools, and the liberty of indifference; betwixt that which is opposed to violence, and that which means a negation of necessity and causes. The first is even the most common sense of the word; and as it is only that species of liberty, which it concerns us to preserve, our thoughts have been principally turned towards it, and have almost universally confounded it with the other.

Secondly, There is a false sensation or experience even of the liberty of indifference; which is regarded as an argument for its real existence. The necessity of any action, whether of matter or of the mind, is not properly a quality in the agent, but in any thinking or intelligent being, who may consider the action, and consists in the determination of his thought to infer its existence from some preceding objects: As liberty or chance, on the other hand, is nothing but the want of that determination, and a certain looseness, which we feel in passing or not passing from the idea of one to that of the other. Now we may observe, that though in reflecting on human actions we seldom feel such a looseness or indifference, yet it very commonly happens, that in performing the actions themselves we are sensible of something like it: And as all related or resembling objects are readily taken for each other, this has been employed as a demonstrative or even an intuitive proof of human liberty. We feel that our actions are subject to our will on most occasions, and imagine we feel that the will itself is subject to nothing; because when by a denial of it we are provoked to try, we feel that it moves easily every way, and produces an image of itself even on that side, on which it did not settle. This image or faint motion, we persuade ourselves, could have been compleated into the thing itself; because, should that be denyed, we find, upon a second trial, that it can.

But these efforts are all in vain; and whatever capricious and irregular actions we may perform; as the desire of showing our liberty is the sole motive of our actions; we can never free ourselves from the bonds of necessity. We may imagine we feel a liberty within ourselves; but a spectator can commonly infer our actions from our motives and character; and even where he cannot, he concludes in general, that he might, were he perfectly acquainted with every circumstance of our situation and temper, and the most secret springs of our complexion and disposition. Now this is the very essence of necessity, according to the foregoing doctrine.

A third reason why the doctrine of liberty has generally been better received in the world, than its antagonist, proceeds from religion, which has been very unnecessarily interested in this question. There is no method of reasoning more common, and yet none more blameable, than in philosophical debates to endeavour to refute any hypothesis by a pretext of its dangerous consequences to religion and morality. When any opinion leads us into absurdities, it is certainly false; but it is not certain an opinion is false, because it is of dangerous consequence. Such topics, therefore, ought entirely to be foreborn, as serving nothing to the discovery of truth, but only to make the person of an antagonist odious. This I observe in general, without pretending to draw any advantage from it.

I submit myself frankly to an examination of this kind, and dare venture to affirm, that the doctrine of necessity, according to my explication of it, is not only innocent, but even advantageous to religion and morality.