Very characteristic was the tireless polemic which Locke carried on against Descartes. The outraged plain facts had to be defended against sweeping and arbitrary theories. There were no innate ideas or maxims: children were not born murmuring that things equal to the same thing were equal to one another: and an urchin knew that pain was caused by the paternal slipper before he reflected philosophically that everything must have a cause. Again, extension was not the essence of matter, which must be solid as well, to be distinguishable from empty space. Finally, thinking was not the essence of the soul: a man, without dying, might lose consciousness: this often happened, or at least could not be prevented from happening by a definition framed by a French philosopher. These protests were evidently justified by common sense: yet they missed the speculative radicalism and depth of the Cartesian doctrines, which had struck the keynotes of all modern philosophy and science: for they assumed, for the first time in history, the transcendental point of view. No wonder that Locke could not do justice to this great novelty: Descartes himself did not do so, but ignored his subjective first principles in the development of his system; and it was not until adopted by Kant, or rather by Fichte, that the transcendental method showed its true colours. Even today philosophers fumble with it, patching soliloquy with physics and physics with soliloquy. Moreover, Locke's misunderstandings of Descartes were partly justified by the latter's verbal concessions to tradition and authority. A man who has a clear head, and like Descartes is rendered by his aristocratic pride both courteous and disdainful, may readily conform to usage in his language, and even in his personal sentiments, without taking either too seriously: he is not struggling to free his own mind, which is free already, nor very hopeful of freeing that of most people. The innate ideas were not explicit thoughts but categories employed unwittingly, as people in speaking conform to the grammar of the vernacular without being aware that they do so. As for extension being the essence of matter, since matter existed and was a substance, it would always have been more than its essence: a sort of ether the parts of which might move and might have different and calculable dynamic values. The gist of this definition of matter was to clear the decks for scientific calculation, by removing from nature the moral density and moral magic with which the Socratic philosophy had encumbered it. Science would be employed in describing the movements of bodies, leaving it for the senses and feelings to appreciate the cross-lights that might be generated in the process. Though not following the technique of Descartes, the physics of our own day realises his ideal, and traces in nature a mathematical dynamism, perfectly sufficient for exact prevision and mechanical art.