Now, one of the fallacies of the argument of the necessitarian is, that it is an attempt to draw a conclusion from the axiomatical truth above referred to, as from the major of a syllogism. Every such attempt must necessarily be vain and fruitless. “Axioms,” justly remarks Mr. Locke, “are not the foundations on which any of the sciences are built.” And again, “It was not the influence of those maxims which are taken for principles in mathematics, that hath led the masters of that science into the wonderful discoveries they have made. Let a man of good parts know all the maxims generally made use of in mathematics never so perfectly, and contemplate their extent and consequences as much as he pleases, he will, by their assistance, I suppose, scarce ever come to know, that the square of the hypothenuse in a right-angled triangle, is equal to the squares of the two other sides. The knowledge, that the whole is equal to the parts, and, if you take equals from equals, the remainder will be equal, helped him not, I presume, to this demonstration. And a man may, I think, pore long enough on those axioms, without ever seeing one jot the more of mathematical truths.”
The same doctrine is still more distinctly stated by Dugald Stewart. “If by the first principles of a science,” says he, “be meant those fundamental propositions from which its remoter truths are derived, the axioms cannot, with any consistency, be called the first principles of mathematics. They have not, (it will be admitted,) the most distant analogy to what are called the first principles of natural philosophy:—to those general facts, for example, of the gravity and elasticity of the air, from which may be deduced, as consequences, the suspension of the mercury in the Torricellian tube, and its fall when carried up to an eminence. According to this meaning of the word, the first principles of mathematical science are, not the axioms but the definitions; which definitions hold, in mathematics, precisely the same place that is held in natural philosophy by such general facts as have now been referred to.”
But the doctrine in question rests upon a firmer basis than that of human authority. Let any man examine the demonstrations in geometry, and attentively consider the principles from which the conclusions of that science are deduced, and he will find that they are definitions, and not axioms. He will find; that the properties of the triangle are derived from the definition of a triangle, and those of a circle from the definition of a circle. And then let him try his own skill upon the axioms of that science; let him arrange them and combine them in all possible ways; let him compare them together as long as he pleases, and determine for himself, whether they can be made to yield a single logical inference. If the question is thus brought to the test of an actual experience, I think it is not difficult to foresee, that the decision must be in favour of the doctrine of Stewart, and that it will be seen, that no such proposition as that whatever is, is, can even constitute the postulate, or first principle, in any sound argument; and that it is only from general facts, such as are ascertained by observation and experience, that we can derive logical consequences of any kind whatever, either in relation to matter or to mind.
If there is any truth in the foregoing remarks, or correctness in the position of Locke and Stewart, it is certainly one of the capital errors of Edwards, as well as of other necessitarians, that he has undertaken to deduce his doctrine from a metaphysical axiom, or identical proposition.
Supposing this to be the case, how has it happened, it may be asked, that the argument of the necessitarian has appeared so conclusive to himself, as well as unanswerable to others? The reason is plain. Having set out with a proposition, which is barren of all consequences, as the basis of his argument, it became necessary, in order to arrive at the destined conclusion, to assume, somewhere and somehow, in the course of his reasoning, the very point which he had undertaken to prove. Accordingly, this has been done; and the tacit assumption of the point in dispute seems not to have been suspected by him.
The justice of this remark may be shown, by a reference to the argument of the necessitarian. When this is reduced to the form of a syllogism, it stands thus: Every effect has a cause; a volition is an effect; and, therefore, a volition has a cause. In the middle term, which assumes that a volition is an effect, the point in dispute is taken for granted, the whole question is completely begged.
If we take the words in any sense, yet as they are correlative terms, the maxim that every effect must have a cause is self-evident; and hence, no conclusion can be drawn from it, unless the conclusion intended to be drawn is assumed in the middle term of the syllogism. It either begs the question, or it decides nothing to the purpose. It is true, that every change in nature must have a cause; that is to say, it is in some sense of the word an effect, and consequently must have a corresponding cause; but in what sense does every act of the mind come under the idea and definition of an effect? This is the question. Is it brought to pass by the prior action of motive? Is it necessitated? Upon this precise question, the maxim that every change must have a cause can throw no light; it only seems to refer to this point, by means of the very convenient ambiguity of the terms in which it is expressed. The necessitarian never fails to avail himself of this ambiguity. He seems both to himself and to the spectator to be carrying on a “great demonstration;” and this is one reason, perhaps, why the mind is diverted from the sophistical tricks, the metaphysical jugglery, by which both are deceived. Let us look a little more narrowly at this pretended demonstration.
The maxim in question is applied to volition; every change in nature, even the voluntary acts of the mind, must have a cause. Now according to Edwards’ explanation of the term, this is a proposition which, I will venture to say, no man in his right mind ever ventured to deny. It is true, that President Edwards tells us of those, who “imagine that a volition has no cause, or that it produces itself;” and he has very well compared this to the absurdity of supposing, “that I gave myself my own being, or that I came into being without a cause,” p. 277. But who ever held such a doctrine? Did any man, in his right mind, ever contend that “a volition could produce itself,” can arise out of nothing, and bring itself into existence? If so, they were certainly beyond the reach of logic; they stood in need of the physician. I have never been so unfortunate as to meet with any advocate of free-agency, either in actual life or in history, who supposed that a volition arose out of nothing, without any cause of its existence, or that it produced itself. They have all maintained, with one consent, that the mind is the cause of volition. Is the mind nothing? If a man should say, as so many have said, that the mind produces its own volitions, is that equivalent to saying, that nothing produces it; that it comes “into being accidentally, without any cause of its being?” Such is the broad caricature of their doctrine, which is repeatedly given by President Edwards.
It is freely admitted, and the advocates of free-agency have always admitted, that volition has a cause, as that word is frequently used by Edwards. He tells us, that by cause he sometimes means any antecedent, whether it exerts any positive influence or no. Now, in this sense, it is conceded by the advocates of free-agency, that motive itself is the cause of volition. This is the question: Is motive the efficient, or producing cause of volition? This is the question, I say; but Edwards frequently loses sight of it in a mist of ambiguities; and he lays around him in the dark, with such prodigious strength, that if his adversaries were not altogether imaginary beings, and therefore impassible to his ponderous blows, I have no doubt he would have slain more of them than ever Samson did of the Philistines.
The manner in which the necessitarian speaks of cause in his maxims, and reasonings, and pretended demonstrations, is of very great service to him. It includes, as we are told, every condition or cause of volition; (what a heterogeneous mass!) every thing without which volition could not come to pass. Yea, it is used in this sense, when it is said that motive is the cause of volition. What shall we do, then, with this broad, this most ambiguous proposition? Shall we deny it? If so, then we deny that volition has any cause of its existence, and fall into the great absurdity of supposing “volition to produce itself.” Shall we assent to it, then? If so, we really admit that motive is the efficient cause of volition; and thus, by denying, we are made to reject our own doctrine, while, by affirming, we are made to receive that of our opponents. This way of proposing the doctrine of necessity very strongly reminds one of a certain trick in legislation, by which such things are forced into a bill, that in voting upon it, you must either reject what you most earnestly desire, or else sanction and support what you most earnestly detest. We should, therefore, neither affirm nor deny the whole proposition as it is set forth by the necessitarian; we should touch it with the dissecting knife, and cure it of its manifold infirmities.