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idols were likely to return, even after the reformation ofscience, and to avail themselves of the real discoveriesthat might have been made, for giving a colour to theirdeceptions. These idols he divides into four classes, towhich he gives names, fantastical no doubt, but abund-antly significant. The first are the “ idola tribus”(idols of the tribe) ; the causes of error founded inhuman nature in general, or on principles common toall mankind. “ The mind,” he observes, “ is not like aplane mirror, which reflects the images of things exactlyas they are; it is like a mirror of an uneven surface,which combines its own figure with the figures of theobjects it represents.” Among the idols of this class,we may reckon the propensity which there is in all mento find in nature a greater degree of order, simplicity,and regularity, than is actually indicated by observation.Thus, as soon as men perceived the orbits of the planetsto be round, they immediately supposed them to hecircles, and the motion in these circles uniform; and tothese hypotheses, so rashly and gratuitously assumed,the astronomers of all antiquity laboured incessantly toreconcile their observations. The propensity whichBacon has here characterised so well, is the same thathas been since his time known by the name of the spiritof system; and the history of modern science fully jus.tifies his anticipation, that this cause of error wouldcontinue to infect the renovated philosophy: and it islikely always to be so, because, unfortunately, the illu-sion is founded on the same principle of association andcombination from which our love of knowledge take itsrise.

2d. The “ idola specus” (of the den) are those whichspring from the peculiar character of the individual. Heconceives each individual having his own dark cavernor den, into which the light is imperfectly admitted,and in the obscurity of which a tutelary idol lurks, atwhose shrine truth is often sacrificed. He here re-marks, that one great distinction in the capacities ofmen is derived from this, that some minds are besto 4