 This account of the ideological role of our conceptions of human nature and of the best political arrangement shows Althusser to differ little from interpretations of Marx which hold that political ideologies are the product of and serve existing economic relations. However, and as was detailed above, Althusser rejects the simple understanding of causality offered by this model in which economic practices order consciousness and our cultural practices. He also rejects the philosophy of history that often accompanies this model. This philosophy has it that certain economic practices not only generate corresponding cultural practices, but that there is a pattern to economic development in which each economic order inexorably leads to its own demise and replacement by a different economic system. In this understanding of history, feudalism must lead to capitalism and capitalism to socialism. Althusser, however, argues against the idea that history has a subject (such as the economy or human agency) and that history has a goal (such as communism or human freedom). History, for Althusser, is a process without a subject. There are patterns and orders to historical life and there is historical change. However, there is no necessity to any of these transformations and history does not necessarily progress. Transformations do occur. However, they do so only when the contradictions and levels of development inherent in a mode of production allow for such change.