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. These criticisms were disturbing for those minds who found entire satisfaction in Science or rather in the sciences, but they were somewhat general. Ravaisson’s work inculcated a spirit rather than sustained a dialectic. Its chief value lay in the inspiration which it imparted to subsequent thinkers who endeavoured to work out his general ideas with greater precision.