Many persons have doubtless been deceived into believing that the theory involves the denial of all influence to idealistic or spiritual factors, and the assumption that economic forces _alone_ determine the course of historical development. Much of the criticism of the theory, especially by the Germans, rests upon that assumption. The theory is attacked, also, as being sordid and brutal upon the same false assumption that it implies that men are governed solely by their economic _interests_, that individual conduct is never inspired by anything higher than the economic interest of the individual. These are misconceptions of the theory, due, no doubt, to the overemphasis placed upon it by its authors--a common experience of new doctrines--and, above all, the exaggerations of too zealous, unrestrained disciples. There is a wise saying of Schiller's which suggests the spirit in which these exaggerations of a great truth--exaggerations by which it becomes falsehood--should be regarded: "Rarely do we reach truth, except through extremes--we must have foolishness ... even to exhaustion, before we arrive at the beautiful goal of calm wisdom."[68] When it is contended that the "Civil War was at bottom a struggle between two economic principles,"[69] we have the presentation of an important truth, the key to the proper understanding of a great historical event. But when that important fact is exaggerated and torn from its legitimate place to suit the propaganda of a theory, and we are asked to believe that Garrison, Lovejoy, and other abolitionists were inspired solely by economic motives, that the urge and passion of human freedom did not enter into their souls, we are forced to reject it. But let it be clearly understood that it forms no part of the theory, that it is even expressly denied in the very terms in which Marx and Engels formulated the theory, and that its authors repudiated such perversions of it.