Many social theories have been called scientific, but no one has insisted more than Marx on the scientific nature of his system of thought. It is the purpose of this article to examine the ambitious claim of Marxism to be the only real science of society. Dialectical materialism may be omitted from consideration since it concerns not science but philosophy (or even metaphysics), and in any case it is the Marxist social theory, or historical materialism, for which the claim of science is most insistently made.
There is no need to give here the details of Marx's historical materialism. The main point to be kept in mind is Marx's assumption, lying behind the entire body of his theory, that history and society move according to a pattern of knowable laws, the so-called “laws of motion” of society; and that Marx claims to have done nothing more than to have laid bare these laws. If Marx is right he obviously ranks as the greatest social scientist of all time. If he is not right he is a misguided and fanatical genius who has led man's thought up a long blind alley.
A preliminary word on the application of scientific methods to the study of society may not be out of place. The purposes of study, whether in the natural or social sciences, are the same: to explain how, to accomplish a practical result, or to predict. These three criteria may also be used to test a scientific theory. There are of course certain special difficulties in the social sciences, difficulties arising (to select from many reasons) because of the nature of the data, or because inference may so easily be confused with fact, or because merely studying the behaviour of people and publishing the results may affect the very behaviour being studied.