And although, during the eighteenth century, this philosophy persisted, and was considerably reinforced (with the help of further discoveries in the realm of physics) by the school of Holbach and Diderot, yet it had still to face the radical criticism of Kant. This criticism, as we shall remember, indicated that the mechanical view is a way in which the human mind--owing to its constitution--regards phenomena. If it is to understand them, the human mind cannot help viewing them in that fashion; it must subject things to the mould in which all its thought is cast. Mechanism is the _medium_ through which the mind understands phenomena. It belongs not to the things in themselves, but to our way of understanding them. And attached to this radical criticism of mechanical notions, was an idealistic philosophy of the most genuinely religious and spiritual character. Kantian idealism is one of those contributions to human thought behind which we shall not again regress. It is a phenomenon of incalculable value and importance. The immediate results of Kant's critical idealism was a luxuriant growth of a spiritual type of philosophy upon the ground he had cleared and prepared. Romanticism may be regarded as a revolt of those sides of human nature upon which the tyranny of mechanism pressed hardest--religion, speculation, poetry, music, art. "You may expel nature with a pitchfork, but she persists in returning." The Horatian remark is true also of the human mind; you may try to weed out religion and poetry, but your success will only be temporary; for nature herself is more persistent than the most earnest of materialists and (what is more) she outlives him. And with regard to the materialist or mechanistic view, it is highly interesting to note that its greatest attraction has consisted in something which, strictly speaking, is not its own property. In the eighteenth century in France, and in the nineteenth century in Germany and England, the popularity of this view was derived from its altogether illegitimate association with a high moral and social idealism, which (it is only too evident) had been borrowed--without sufficient acknowledgment--from the Christian tradition. The rather self-conscious atheism (for instance) of Shelley or Byron--which they had presumably derived from Diderot and his contemporaries--was less a denial of God than an affirmation of the rights of humanity. This generous philosophy of revolt from contemporary tyranny and pharisaism is atheistic only in name. The callous and cynical powers, both political and ecclesiastical, that were the object of their bitter attacks were the embodiments of atheism, for "He alone is the true atheist to whom the predicates of the Divine Being, e.g. love, wisdom, justice, are nothing."[79]