The author analyzes the issue of relation of the history of medicine to relativism. He pinpoints that it was the history of science that has been used nowadays as the basis for speculations on any type of science. Perceiving the contemporary history of science as a descriptive discipline is deemed by him a serious challenge to the historians of medicine. He believes that the studies conducted by the historians of medicine may expert a huge impact on the vevelopment of individual medical desciplines. The author profoundly analyzes the thesis presented by relativists that the cognitive value of any science is relative. He takes into consideration the views of philosophers, sociologists and historians. As a result of his speculations, J. Strojnowski draws the conclusion that scientific theses are more or less true, though none of them is close to the truth. The notion of the truth does not function in the science, but it may not be omitted in the study of the progress of human knowledge. The notion belongs to the philosophy of science and refers, in particular, to a scientist's attitude. Scientists must believe in the truth, although they know they will never reach it.