No other works of the author, contradictory as have been the opinions of them, have provoked such a diversity of criticism as these.

To some persons they represent a temporary aberration of genius rather than any serious thought or definite purpose; while others regard them as surpassing in bold and original speculation, profound analysis of character, and thrilling interest, all of the author's other works.

The truth, we believe, lies midway between these extremes.

It is questionable whether the introduction into a novel of such subjects as are discussed in these romances be not an offence against good sense and good taste; but it is as unreasonable to deny the vigour and originality of their author's conceptions, as to deny that the execution is imperfect, and, at times, bungling and absurd.
It has been justly said that the present half century has witnessed the rise and triumphs of science, the extent and marvels of which even Bacon's fancy never conceived, simultaneously with superstitions grosser than any which Bacon's age believed.

"The one is, in fact, the natural reaction from the other.