Such was Hume's psychology; an attempt to push analysis to its ultimate limits; valuable in its method, even if defective in its results; a striking example of the acuteness and subtle penetration of its author. There is another branch of his philosophy in which he is regarded as a metaphysical sceptic, in reference to the passage of the mind outwards, by means of its own sensations and ideas, into the knowledge of real being, wherein he takes part with Berkeley, extending to the inner world of soul the scepticism which that philosopher had applied to the outer world of matter. In the psychological branch Hume is a sensationalist, in the ontological a sceptic. The latter however has no relation to our present subject. It is from the former that his views on religion are deduced. In no writer is the logical dependence of religious opinion on metaphysical principles visible in a more instructive manner. For we perceive that the influence adverse to religion in his case was not merely the result of rival metaphysical dogmas opposed to religion, such as were seen in the Pantheists of Padua, or in Spinoza; nor even the opposition caused by the adoption of a different standard of truth for pronouncing on revelation, as in his fellow English deists; but it sprung from the application of the subjective psychological inquiry into the limits of religious knowledge, as a means for criticising not only the logical strength of the evidence of religion, but specially the historic evidence of testimony. We consequently see the influence exercised by the subjective branch of metaphysical inquiries in the discussion not only of the logic of religion, but also of the logic of the historic aspect of it.
Hume's religious speculations[480] relate to three points:—to the argument for the attributes of God, drawn from final causes; to the doctrine of Providence, and future rewards and punishments; and to the evidence of testimony as the proof of miracles. Though he does not conduct an open assault in reference to any [pg 150] of them, but only suggests doubts, yet in each case his insinuations sap so completely the very proof, that it is clear that they are intended as grounds not merely for doubt, but for disbelief. His doctrine of sensation is the clue to his remarks on the two former. He argues that we can draw no sound inferences on the questions, because the subjects lie beyond the range of sensational experience. It is however in consequence of his remarks on the last of the three subjects in his essay on Miracles that his name has become famous in the history of free thought.
The essay consists of two parts. In the first he shows that miracles are incapable of proof by testimony. Belief is in proportion to evidence. Evidence rests on sensational experience. Accordingly the testimony to the uniformity of nature being universal, and that which exists in favour of the occurrence of a miracle, or violation of the laws of nature, being partial, the former must outweigh the latter. In the second he shows, that if this is true, provided the testimony be of the highest kind, much more will it be so in actual cases; inasmuch as no miracle is recorded, the evidence for which reaches to this high standard. He explains the elements of weakness in the evidence; such as the predisposition of mankind to believe prodigies, forged miracles, the decrease of miracles with the progress of civilization, the force of rival testimony in disproof of them, which he illustrates by historic examples, such as the alleged miracles of Vespasian, Apollonius, and the Jansenist Abbé Paris.[481] The conclusion is, that miracles cannot be so shown to occur as to be used as the basis of proof for a revelation; and that a revelation, if believed, must rest on other evidence.
The argument accordingly is briefly, that testimony cannot establish a fact which contradicts a law of nature; [pg 151] the narrower induction cannot disprove the wider. The reasoning has been used in subsequent controversy[482] with only a slight increase of force, or alteration of statement. The great and undeniable discoveries of astronomy had convinced men in the age of Hume of the existence of an order of nature; and modern discovery has not increased the proof of this in kind, though it has heightened it in degree, by showing that as knowledge spreads the range of the operation of fixed law is seen to extend more widely; and apparent exceptions are found to be due to our ignorance of the presence of a law, not to its absence. The statement of the difficulty would accordingly now be altered by the introduction of a slight modification. Instead of urging that testimony cannot prove the historic reality of the fact which we call a miracle, the assertion would be made that it can only attest the existence of it as a wonder, and is unable to prove that it is anything but an accidental result of an unknown cause. A miracle differs from a wonder, in that it is an effect wrought by the direct interposition of the Creator and Governor of nature, for the purpose of revealing a message or attesting a revelation. That testimony can substantiate wonders, but not distinguish the miracle from the wonder, is the modern form of the difficulty.
The connexion of Hume's view with his metaphysical principles will be evident. If nature be known only through the senses, cause is only the material antecedent visible to the senses. Nature is not seen to be the sphere of the operation of God's regular will; and the sole proof of interference with nature must be a balancing of inductions. It will be clear also that the true method of replying to Hume has been rightly perceived by those who consider that the difficulty must be met by philosophy, and not by history.
Suppose the historic evidence sufficient to attest the wonder, it does not prove that the wonder is a miracle. The presumption in favour of this may be indefinitely [pg 152] increased by the peculiarity of the circumstances, which frequently forbid the idea of a mere marvel; but the real proof must depend upon the previous conception, which we bring to bear upon the question, in respect to the being and attributes of God, and His relation to nature. The antecedent probability converts the wonder into a miracle. It acts in two ways. It obliterates the cold materialistic view of the regularity of nature which regards material laws to be unalterable, and the world to be a machine; and it adds logical force to the weaker induction, so as to allow it to outweigh the stronger. No testimony can substantiate the interference with a law of nature, unless we first believe on independent grounds that there is a God who has the power and will to interfere.[483] Philosophy must accordingly establish the antecedent possibility of miracles; the attribute of power in God to effect the interruption, and of love in God to prompt him to do it. The condition therefore of attaining this conception must be by holding to a monotheistic conception of God as a being possessing a personal will, and regarding mind and will as the rule by which to interpret nature and law,[484] and not conversely measuring the mental by the material. In this manner law becomes the operation of God's personal fixed will, and miracle the interposition of his personal free will.
It will be perceived that in distinguishing miracle from wonder, we also take into account the final cause of the alleged interposition as a reason weighty enough to call forth divine interposition. As soon as we introduce the idea of a personal intelligent God, we regard Him as acting with a motive, and measure His purposes, [pg 153] partly by analogy to ourselves, partly by the moral circumstances which demand the interposition.[485]
These remarks may furnish the solution of the puzzle whether the miracle proves the doctrine, or the doctrine the miracle.[486] Undoubtedly the miracle proves the particular doctrine which it claims to attest; but a doctrine of some kind, though not the special one in point, some moral conception of the Almighty's nature and character, must precede, in order to give the criterion for distinguishing miracle from mere wonder. Miracles prove the doctrine which they are intended to attest; but doctrines of a still more general character are required to prove the miracle.
This examination of the doctrine of Hume will not only illustrate our main position, of the influence of intellectual and philosophical causes in generating doubt, or at least in directing free thought into a sceptical tendency, but will illustrate the application made of that special department of metaphysics which relates to the test of truth, to discredit the literary proof of revelation as an historic system.
We have now sketched the natural history of deism, by showing that in this as in former periods the forms which free thought assumed were determined by the philosophy, and, in a slighter degree, by the critical knowledge of the age.