The ambiguity of the term cause is, indeed, one of the most powerful weapons, both of attack and defence, in the whole armory of the necessitarian. Do you affirm the mind to be the cause of volition? Then, forthwith, as if the word could have only one meaning, it is alleged, that if the mind is the cause of volition, it can cause it only by a preceding volition; and so on ad infinitum. Hence, your doctrine must needs be absurd; because the word is understood, yea, and will be understood, in its most restrained and narrow sense. But do you deny motive to be the cause of volition? Then, how absurd are you again; you are no longer understood to use the word in the same sense; you now mean, not only that motive is not the producing cause of volition, but that there is absolutely nothing upon which it depends for its existence, and that “it produces itself.” Does Edwards affirm that motive is the cause of volition; that motive causes volition to arise and come forth into existence; that it is not merely “the negative occasion” thereof, but the cause in the most proper sense of the word; that it is “the effectual power which produces volition?” What then? Dare you assert, in the face of such teaching, that motive is not the cause of volition? If so, then you are a most obstinate and perverse caviller; and you are silenced by the information that he sometimes uses the word cause to signify any antecedent, whether it has any positive influence or no. Yea, he gives this information, he declares, to “cut off occasion from any that might seek occasion to cavil and object against his doctrine,” p. 51. These, and many other things of the same kind, are to be found in the writings of Day, and Edwards, and Collins, and Hobbes; and whosoever may be pleased to follow them, through all the doublings and windings of their logic, may do so at his leisure. It is sufficient for my present purpose to remark, that Edwards has included a number of different ideas in his definition of cause; and that he turns from the one to the other of these ideas, just as it suits the exigencies of his argument. It is in this way, as we have seen, that the famous maxim, that every change in nature must have a cause, has been made to serve his purpose.
He did not look at a volition and an effect, so as to mark their differences narrowly, and to proceed in his reasonings according to them; he set out with the great and universal truth, that every change in the universe must have a cause; from which lofty position the differences of things in this nether world were invisible. Having secured this position to his entire satisfaction, being firmly persuaded in his own mind, that “nonentity could not bring forth,” he supposed he had gained a strong foothold; and from thence he proceeded to reason downward to what actually takes place in this lower world!
We are but “the humble servants and interpreters of nature,” and we “can understand her operations only in so far as we have observed them.” The necessitarian takes higher ground than this. He disdains the humble and patient task of observation. He plants his foot upon an eternal and immutable axiom; and, turning away from the study of what is, he magisterially pronounces what must be.
It is easy to see how he constructs his system. Every change in nature must have a cause, says he; this is very true; there is no truth in the world more certain, according to the sense in which he frequently understands it. If he means to assert, that nothing, whether it be an entity, or an attribute, or a mode, can bring itself into existence, no one disputes his doctrine. It is most true, that there can be no choice without a mind that chooses, or an object in view of which it chooses; a mind, an object, and a desire, (if you please,) are the indispensable prerequisites, the invariable antecedents, to volition; but there is an immense chasm between this position and the doctrine, that the mind cannot put forth a volition, unless it is made to do so by the action of something else upon it. This immense chasm, the necessitarian can cross only by stepping over from one branch of his ambiguous proposition to another; he either does this, or he does not reach the point in controversy at all.
[SECTION VII.]
OF THE APPLICATION OF THE MAXIM THAT EVERY EFFECT MUST HAVE A CAUSE.
In the last section I considered the application of the maxim, “that every effect must have a cause,” to the question of necessity. This maxim figures so largely in every scheme of necessity, and it is relied upon with so much confidence, that I shall present some further views respecting its true nature and application. The necessitarian may see the truth of this maxim clearly, but he applies it vaguely.
He is always saying, “that if we give up this great principle of common sense, then there is no reasoning from effect to cause; and we cannot prove the existence of a God.” Now I propose to show that we need not give up “this great principle of common sense;” that we may continue to reason from effect to cause, and so reach the conclusion that there is a God, by one of the most incontrovertible of all our mental processes; and yet we may, with perfect consistency, refuse to apply the maxim in question to human actions or volitions. In other words, that we may freely admit the principle in question, and yet reject the application which the necessitarian is accustomed to make of it.
In order to do this in a perspicuous and satisfactory manner, let us consider the occasion on which we first became acquainted with the truth of the principle, that every effect must have a cause. Let us consider the circumstances under which it is first suggested to the mind. Whence, then, do we derive the ideas of cause and effect, and of the necessary connection between them?
Locke, it is well known, supposed that we might derive the idea of causation by reflecting on the changes which take place in the external world. The fallacy of this supposition has been fully shown by Hume, and Brown, and Consin. In the refutation of Locke’s notion, these celebrated philosophers were undoubtedly right; but the two first were wrong in the conclusion that we have no idea of power at all. Because the ideas of power and causation are not suggested by the changes of the material world, it does not follow that we have no such ideas in reality; that the only notion we have of causation is that of an invariable antecedence.