It has been well remarked, that that writer would be equally in danger of error who would assign very abstruse motives for the conduct of great bodies of men, or very obvious causes for the great phenomena of nature. The motives of the masses,--on a level always with the average comprehension,--are never abstruse; the causes of the phenomena, on the other hand, are never obvious. And when these last are hastily sought after, not from any devotion to scientific truth, or any genuine love of it, but for some purpose of controversy, we may receive it as a sure and certain fact that they will not be found. Some mere plausibility will be produced instead, bearing on its front an obviousness favorable mayhap to its reception for the time by the vulgar, but in reality fatal to its claims in the estimate of all deep thinkers; while truth will meanwhile lie concealed far below, in the bottom of her well, until patiently solicited forth by some previously unthought of process, in the character of some wholly unanticipated result. Such, in the history of science, has been the course and character of error on the one hand, and of actual discovery on the other: the error has been always comparatively obvious,--the discovery unexpected and abstruse. And as men descend in the scale of accomplishment or intellect, a nearer and yet nearer approximation takes place between their conceptions of the causes of the occult processes of nature, and the common and obvious motives which influence large masses of their fellows; until at length the sublime contrivances of the universe sink, in their interpretation of them, into the clumsy expedients of a bungling mechanism.