The most central claim of social constructivism is that no certain knowledge is possible, and in particular no certian knowledge of mathematice is possible.Concerning empirical knowledge,this thesis is one that is subscribed to by many philosophers, these include continental sceptics beginning with,Descartes; British empiricists such as Hume; American pragmatists such as james and Dewey; some modern American philosophers of science,inclluding Popper,Kuhn,Feyerabend, Lakatos and Laudan.