other; nor would he fix the decade in which English landlords, or capitalists, or labourers became sufficiently free from medieval restraints to allow his ideal groups some semblance of truth. In fine, no competent judge will deny that these and all social scientists must ideally construct definitions which concrete facts only temporarily and indistinctly contain—unless, indeed, we are content to look in despair on that vast moving mass which we call "social life" and give up the attempt to understand and explain it altogether. The search after minute distinctions in social classification and minute time-marks in social evolution is in fact an eidolon tribûs. An image of the individual's life is insensibly transferred to the action of men in groups, and the distinctness of an individual's personality and career is required from social classifications the very essence of which is their immunity from that defined birth and death which give to individual life its clear-cut limits. The concrete existence of the individual in space is, likewise, sought in group life, and we perpetually forget that, even in the simplest cases, a group is essentially an abstraction drawing up an immense detail of individualities into an apex of common points which are found in actual life diverging into many degrees of diversity. While we thus erroneously seek the unity and personality of the individual in groups, the common standards of chronology are likewise applied by universal consent to the life of groups as to that of individuals. Let the first year of our social memory be once settled, and, whether it be an Egyptian dynasty or the first celebration of public games, or the birth or the death or the flight of a prophet, we are ready to measure back by year and day to this arbitrary terminus the lives of individuals and of groups alike. The observer of organic nature knows by what