The ever-deepening investigations of science confront, in present times, the question of whether the spontaneous acquisition of knowledge is not in conflict with the basic values of man and human society. In particular, biological and medical investigation faces the problem of whether it should, in certain directions, continue its progress, or whether, temporarily or definitively, it should call a halt (genetic engineering). Also, in the area of technical projects and the investigation of space, we are seeing the danger emerging of a threat to the natural and life environment of man. These realities call for discussion, by the academic community, of the role of values and ethical principles in the progress of scientific investigation. In the social and cultural sciences the question the cultural and value context of human knowledge is coming to the fore. In the philosophy of science the question arises as to whether this situation influences our conception of scientific rationality. Scientific rationality does not present itself, once and for all, as a well-defined category. Its content changes with the development of knowledge and has, therefore, more of an empirical, descriptive character dependent on the advance of knowledge. In addition to internal criteria, which characterised by the development of scientific praxis, and which constitute the basis of scientific methodology, there now arise new value criteria which are forming the common endeavour of the natural scientists, sociologists and philosophers. Scientific knowledge and theory is not value-neutral. The value and ethical dimension has an inner constitutive influence on advancing knowledge and enters into scientific methodology. This all contributes to the character of the contemporary picture of the world, or world-view which, as a component in social determination, likewise influences scientific rationality.