Abstract

It is argued that ideas and theories often evolve into preconceptions of our perceptions. Such evolution is implicit in Heidegger's notion of truths of alethia. The description of this process holds implications for the traditional givenness of humans for themselves in terms of the changabllity of absolute presuppositions. Among the implications are 1. the insufficiency of the historical mode for explaining changes in human self-perception; 2. the inadequacy of radical subjectivism and environmentalism; 3. a radical contingency and complexity to the course of human conceptualization; and 4. the awareness that human efforts can influence alterations in preconceptions. The influence of modern brain theory is subject to these conditions.