The true cause of this nervous state cannot, nay, must not, be confided to the world: the honour of his darling theory will always be dearer to his pride than the confession of even slight doubts which may shake its truth.

It is a curious fact which we have but recently discovered, that ROUSSEAU was disturbed by a terror he experienced, and which we well know was not unfounded, that his theories of education were false and absurd.

He could not endure to read a page in his own "Emile"[A] without disgust after the work had been published! He acknowledged that there were more suffrages against his notions than for them.

"I am not displeased," says he, "with myself on the style and eloquence, but I still dread that my writings are good for nothing at the bottom, and that all my theories are full of extravagance." [_Je crains toujours que je peche par le fond, et que tous mes systemes ne sont que des extravagances._] HARTLEY with his "Vibrations and Vibrationeles," LEIBNITZ with his "Monads," CUDWORTH with his "Plastic Natures," MALEBRANCHE with his paradoxical doctrine of "Seeing all things in God," and BURNET with his heretical "Theory of the Earth," must unquestionably at times have betrayed an irritability which those about them may have attributed to temper, rather than to genius.
[Footnote A: In a letter by Hume to Blair, written in 1766, apparently first published in the _Literary Gazette_, Nov.

17, 1821.] Is our man of genius--not the victim of fancy, but the slave of truth--a learned author?
Of the living waters of human knowledge it cannot be said that "If a man drink thereof, he shall never thirst again." What volumes remain to open! what manuscript but makes his heart palpitate! There is no term in researches which new facts may not alter, and a single date may not dissolve.