Most of the creations of the intellect or fancy pass away for good after a time that varies between an after-dinner hour and a generation. Some, however, do not. They suffer eclipses but they come back again, and they come back not as unrecognizable elements of a cultural inheritance, but in their individual garb and with their personal scars which people may see and touch. These we may well call the great ones—it is no disadvantage of this definition that it links greatness to vitality. Taken in this sense, this is undoubtedly the word to apply to the message of Marx. But there is an additional advantage to defining greatness by revivals: it thereby becomes independent of our love or hate. We need not believe that a great achievement must necessarily be a source of light or faultless in either fundamental design or details. On the contrary, we may believe it to be a power of darkness; we may think it fundamentally wrong or disagree with it on any number of particular points. In the case of the Marxian system, such adverse judgment or even exact disproof, by its very failure to injure fatally, only serves to bring out the power of the structure.