extended and spread abroad, and have fulfilled the duty which it owes to Physics, as strictly defined in our last lecture. But the true Physical Inquirer always proceeds beyond the Phenomena, seeking only the Law in the Unity of which the Phenomena may be comprehended; and as soon as he has reached the primitive Thought, returning again to the Phenomena in order to test the Thought by its application to them;—undoubtedly with the firm conviction that the validity of the Thought can only be established by its sufficiency for the explanation of the Phenomena, and with the determination to throw it aside should it not be verified in this way. It is verified; and he is thereby satisfied that his conception has been no arbitrary conceit, but a true Thought revealed by Nature herself;—and thus his inspiration is not Mysticism but is to be named Genius. Quite otherwise is it with the Mystic:—he neither proceeds outwards from Empiricism, nor yet does he recognise Empiricism as the judge of his fancies,—but he demands that Nature should regulate herself by his thoughts;—in which he should be perfectly justified, had he only got hold of the right Thoughts, and if he knew how far this a priori conception of Nature can go, at what point it comes to an end, and where Experiment alone can decide.
These fancies of the Mystic, I have said, are neither clear in themselves, nor are they proved, or even capable of theoretical proof which indeed is renounced in the avowal of Incomprehensibility; but yet they may be true, and may therefore be confirmed by our natural sense of Truth, provided they fall within its sphere. How is it then, that they are believed in by their original authors themselves? I am bound to solve this question before we proceed further.
These fancies are, at bottom, as we have shown above, the products of a blind natural thinking-power; which power must necessarily manifest itself in these particular
