If that imaginary individual so convenient for literary illustration, a visitor from Mars, were to alight upon our planet at its present stage of development, and if his intellectual interests induced him to survey the range of terrestrial views of the nature of what is "in heaven above, or on the earth beneath, or in the waters under the earth," to appraise mundane opinion in regard to the perennial problems of mind and matter, of government and society, of life and death, our Martian observer might conceivably report that a limited portion of mankind were guided by beliefs representing the accumulated toil and studious devotion of generations,--the outcome of a slow and tortuous but progressive growth through error and superstition, and at the cost of persecution and bloodshed; that they maintained institutions of learning where the fruits of such thought could be imparted and the seeds cultivated to bear still more richly; but that outside of this respectable yet influential minority, there were endless upholders of utterly unlike notions and of widely diverging beliefs, clamoring like the builders of the tower of Babel in diverse tongues. It is well, at least occasionally, to remember that our conceptions of science and of truth, of the nature of logic and of evidence, are not so universally held as we unreflectingly assume or as we hopefully wish. Almost every one of the fundamental, basal, and indisputable tenets of science is regarded as hopelessly in error by some ardent would-be reformer. One Hampden declares the earth to be a motionless plane with the North Pole as the centre; one Carpenter gives a hundred remarkable reasons why the earth is not round, with a challenge to the scientists of America to disprove them; one Symmes regarded the earth as hollow and habitable within, with openings at the poles, which he offered to explore for the consideration of the "patronage of this and the new worlds;" while Symmes, Jr., explains how the interior is lighted, and that it probably forms the home of the lost tribes of Israel; and one Teed announces, on equally conclusive evidence, that the earth is a "stationary concave cell ... with people, Sun, Moon, Planets, and Stars on the inside," the whole constituting an "alchemico-organic structure, a Gigantic Electro-Magnetic Battery." If we were to pass from opinions regarding the shape of the earth to the many other and complex problems that appeal to human interests, it would be equally easy to collect "ideas" comparable to these in value, evidence, and eccentricity. With this conspicuously pathological outgrowth of brain-functioning,--although its representatives in the literature of the occult are neither few nor far between,--I shall not specifically deal; and yet the general abuse of logic, the helpless flounderings in the mire of delusive analogy, the baseless assumptions, which characterize insane or "crank" productions, are readily found in the literary products of occultism.