He justifies to the scientist the formulation of hypothesis as a necessary working method of co-ordinating in a provisional manner varying phenomena. Many hypotheses and inductions of science are, however, unjustifiable from a strictly logical standpoint, Renouvier reminds us. His chief objection, however, is that those hypotheses and inductions are put forward so frequently as certainties by a science which is dogmatic and surpasses its limits.
Science, Renouvier claims, does not give us a knowledge of the absolute, but an understanding of the relative. It is in the light of his doctrine of relativity and of the application of the law of number that he criticises many of the attitudes adopted by the scientists. Whatever savours of the Absolute or the Infinite he opposes, and his view of cause depends on this. He scorns the fiction of an infinite regress, and affirms real beginnings to various classes of phenomena. Causality is not to be explained, he urges in his Nouvelle Monadologie, save by a harmony. He differs from Leibnitz, however, in claiming in the interests of freedom that this harmony is not pre-established. In meeting the doctrine of the reduction of the complex to the simple, Renouvier cites the case of “reducing” sound, heat, light and electricity to movement. This may be superficially correct as a generality, but Renouvier aptly points out that it overlooks the fact that, although they may all be abstractly characterised as movement, yet there are differences between them as movements which correspond to the differences of sensation they arouse in us.
Renouvier upholds real differences, real beginnings, and, it must be added, a reality behind and beyond the appearances of nature. His Monadologie admits that “we can continue to explain nature mathematically and mechanically, provided we recognise that it is an external appearance—that thought, mind or spirit is at the heart of it.” This links Renouvier to the group of new spiritualists. His attitude to science is akin to theirs. He does not fear science when it confines itself to its proper limits and recognises these. It has no quarrel with philosophy nor philosophy with it. Advance in science involves, he believes, an advance also in theology and in metaphysics.
The sciences are responsible for working out the laws determining the development of the Universe. But between Science, an ideal unachieved, and the sciences which in themselves are so feeble, imperfect and limited, Renouvier claims that General Criticism, or Philosophy, has its place. “In spite of the discredit into which philosophy has fallen in these days, it can and ought to exist. Its object has been always the investigation of God, man, liberty, immortality, the fundamental laws of the sciences. ‘All these intimately connected and interpenetrating problems comprise the domain of philosophy.” In those cases where no science is possible, this seeming impossibility must itself be investigated, and philosophy remains as a “General Criticism” (Critique générale) of our knowledge. “It is this notion,” he says, “which I desired to indicate by banishing the word ‘Philosophy’ from the title of my Essays. The name ought to change when the method changes.”[[28]] Thus Renouvier seeks to establish a “critique” midway between scepticism and dogmatism, and endeavours to found a philosophy which recognises at one and the same time the demands of science et conscience.
[28] Logique, vol. 2, p. 352.
III
On turning to the spiritualist current of thought we find it, like the neo-criticism, no less keen in its criticism of science. The inadequacy of the purely scientific attitude is the recurring theme from Ravaisson to Boutroux, Bergson and Le Roy. The attitude assumed by Ravaisson coloured the whole of the subsequent development of the new spiritualist doctrines, and not least their bearing upon the problem of science and its relation to metaphysics.
Mechanism, Ravaisson pointed out, quoting the classical author upon whom he had himself written so brilliantly (Aristotle), does not explain itself, for it implies a “prime mover,” not itself in motion, but which produces movement by spiritual activity. Ravaisson also refers to the testimony of Leibnitz, who, while agreeing that all is mechanical, carefully added to this statement one to the effect that mechanism itself has a principle which must be looked for outside matter and which is the object of metaphysical research. This spiritual reality is found only, according to Ravaisson, in the power of goodness and beauty—that is to say, in a reality which is not non-scientific but rather ultra-scientific. There are realities, he claims, to which science does not attain.
The explanation of nature presupposes soul or spirit. It is true, Ravaisson admits, that the physical and chemical sciences consider themselves independent of metaphysics; true also that the metaphysician in ignoring the study of those sciences omits much from his estimate of the spirit. Indeed, he cannot well dispense with the results of the sciences. That admission, however, does not do away with the possibility of a true “apologia” for metaphysics. To Newton’s sarcastic remark, “Physics beware of metaphysics,” Hegel replied cogently that this was equivalent to saying, “Physics, keep away from thought.” Spirit, however, cannot be omitted from the account; it is the condition of all that is, the light by which we see that there is such a thing as a material universe. This is the central point of Ravaisson’s philosophy. The sciences of nature may be allowed and encouraged to work diligently upon their own principles, but the very fact that they are individual sciences compels them to admit that they view the whole “piecemeal”. Philosophy seeks to interpret the whole as a whole. Ravaisson quotes Pascal’s saying, “Il faut avoir une pensée de derrière la tête et juger de tout par là.” This pensée de derrière la tête, says Ravaisson, while not preventing the various sciences from speaking in their own tongue, is just the metaphysical or philosophical idea of the whole.
It is claimed, Aristotle used to say, that mathematics have absolutely nothing in common with the idea of the good. “But order, proportion, symmetry, are not these great forms of beauty?” asks Ravaisson. For him there is spirit at the heart of things, an activity, un feu primitif qui est l’âme, which expresses itself in thought, in will and in love. It is a fire which does not burn itself out, because it is enduring spirit, an eternal cause, the absolute substance is this spiritual reality. Where the sciences fall short is that they fail to show that nature is but the refraction of this spirit. This is a fact, however, which both religion and philosophy grasp and uphold.