"This is unquestionably the nature of the principle of induction as proposed by Lord Bacon. Its useful and successful application, however, to the various departments of knowledge,—and there is scarcely any department to which, under suitable modifications, it may not be advantageously applied,—requires much care, attention, and assiduous patience. Bacon, therefore, employs the chief part of the first book of the Novum Organum in exposing the various prejudices and futile anticipations, which he calls the idols of the human mind, in contradistinction to the ideas of the divine mind, or those impressions of truth which are stamped upon the various elements and orders of creation. These idols he ranges under the four general classes, which he quaintly but expressively denominates Idols of the Tribe, Idols of the Den, Idols of the Forum, and Idols of the Theatre. The first class of idols, or prejudices, he represents as naturally inherent in the race of men, on account of the narrowness and imperfection of their views; the second, as peculiar to individuals, and arising from their peculiar habits and pursuits, hence entitled idols of the den or cave; the third, as springing from the mutual intercourse of mankind with each other, hence called idols of the forum or market; and the fourth, as originating in the false and fantastic theories of philosophers, exhibited from age to age as so many scenic representations on the stage of the intellectual world, and therefore appropriately styled idols of the theatre."