The author sees the history of Western Science as the history of a vision and an argument, initiated by the ancient Greeks in their search for principles at once of nature and of argument itself. This scientific vision explored and controlled by argument, and the diversification of both vision and argument by scientific experience and by interaction with the wider contexts of intellectual culture, constitute the long history of European scientific thought. Underlying that development have been specific commitments to conceptions of nature and of science and its intellectual and moral assumptions, accompanied by a recurrent critique; their diversification has generated a series of different styles of scientific thinking and of making theoretical and practical decisions which the work describes.