[Historical context of parasitological studies in tropical area, malaria as an example].

Review paper deals with the historical analysis of intellectual activity of some famous parasitologists working in tropics on malaria in the XIX/XX century: A. Laveran (1845-1922), R. Ross (1857-1932), P. Manson (1844-1922), B. Grassi (1854-1925), and other Nobelprize researchers: P. H. Müller (1899-1965) and J. W. von Jauregg (1857-1940). Those chief investigations are interpreted from the point of view of the so-called anthropology of knowledge based on L. Fleck's (1896-1961) philosophy and sociology of science. Parasitological investigations, especially in the field of malaria, were undertaken in the developed economically countries in answer to the social demands. It was connected with development of colonies and the needs of stabilization of epidemiological situation in tropics. To mid of the eigthies of 19th century the lack of positive effects resulted from the theoretical barriers and conservative thinking style of the European academic society. It caused that great parasitological discoveries of the etiological agents of parasitic diseases (like plasmodia, life cycle in malaria) took place behind university circles. They were done by the physicians - general practitioners--in the colony areas. Doctors A. Laveran, P. Manson and R. Ross were not restricted by traditional standards and the obliging normative concepts in the academic naturalism. Those medical men worked out a new impulse for parasitology and supported an idea based on the rule that each disease should be assigned with the materialistic biological factor (pathogen). In the years 1800-1900 the old and a new concepts were competed in the natural sciences and medicine. Near year 1900 a new way in the context of modern interpretations was brought into general use. It was proved experimentally that etiological theory of parasitic disease was more practically usuful. It resulted in the formation of the effective prophylactic theory as well as the development of research in the field of chemotherapy. For that reason this thinking style was accepted by the state authorities and armies interested in possessing colonies. The governments organized and financed scientific institutes of tropical medicine and the hygienic parasitological journals. Also the researchers (A. Laveran, R. Ross, P. Manson) were rewarded for their epoch-making investigations in tropical disease problems. At the same time the progress in parasitology was prompted and the old theories in old thinking style were eliminated as false because of their practical uselessness. Their followers lost status of authorities. This analysis proved that external factors of science, i.e. social needs in historic periods play real role in the promoting of changes of scientific standards in the perception of new standards. Social needs form the broad social-cultural context of scientific activity and they influence seriously the way of thinking and investigations practice.