One of the outstanding believers in the theory that conflict dominates societal life was Ludwig Gumplowicz (1838–1910). His system of thought begins with the assertion that primitive hordes were the original units of society. Gumplowicz dissented from Herbert Spencer’s belief in the individual as the original societary unit, although he accepted the determinism that is inherent in Spencer’s theory of evolution. Gumplowicz also repudiated Comte’s belief in social amelioration through prevision, but subscribed to Comte’s positivism. According to Gumplowicz, society began with a large number of primitive groups, which were self-sustaining and self-conscious units. Each one of these hordes was a warring group, possessing an instinctive hatred of all other hordes.[XX-1] As these hordes increased in size, the general food supply failed to meet the needs. Consequently, inter-group struggle resulted and the members of the weaker hordes were either destroyed or enslaved. The existence of slaves led to situations of intra-group inequality, which in turn created problems involving justice and injustice. As a result of continual conflicts between groups, there are frequent changes taking place in their personnel. The vanquished are continually being absorbed by victorious groups. In a given successful group two classes are at once established, namely, the victors and the vanquished. Classes are thus continually arising out of new juxtapositions of heterogeneous racial elements.[XX-2] It was in an intense form of group self-interest that Gumplowicz found the mainspring of social progress. This self-interest leads to an exaggerated group appraisement, a strong degree of group unity, a state of warfare between groups--and perhaps progress. Basic to this group self-interest, there are the material needs of the members of the group; the economic desires and the occupational interests; and the moral and spiritual tendencies. The group is bound together by various factors, such as a common social life, a common language, religion, and culture. Gumplowicz advocated a theory of potential race equality. He argued against innate racial superiority and racial inferiority. He doubted the existence of any pure races. Each race is a compound of other races, and hence races are potentially similar in fundamental respects. National progress, therefore, holds no connection with race purity.