In this work we ask ourselves what class of rationality sublies in the scientific - technological debates in the frame of the national systems of innovation. We analyze first, the foundations of the classic model of rationality and the traditional distinction between theoretical rationality or epistémic and the practice. Later, we introduce Nicholas Rescher's theoretical offer from two of his texts: " The fight of the systems " (1995) and " The rationality. A philosophical investigation on the nature and the justification of the reason " (1993). Here we wonder on what there are based the differences of application of the notions of rationality, and if this obeys the nature of disciplinary different areas. Thirdly, we connect the sense of practical, from rationality From the Economic Theory, with his application in the scientific - technological debates. We rescue of Nicholas Rescher, the importance of the cognitive values as reason of the disagreement between philosophers, and think, for analogy, which should be born in mind in other contexts, as that it occupies us here. We support the need of a pluralist vision and relativista, opposite to a slightly realistic position in the search of consensus
