The ISA maintains a Research Committee devoted to "the Body in the Social Sciences." A subfield of the sociology of health and illness that overlaps with cultural sociology is the study of death, dying and bereavement, sometimes referred to broadly as the sociology of death. This topic is exemplified by the work of Douglas Davies and Michael C. Kearl. The sociology of knowledge is the study of the relationship between human thought and the social context within which it arises, and of the effects prevailing ideas have on societies. The term first came into widespread use in the 1920s, when a number of German-speaking theorists, most notably Max Scheler, and Karl Mannheim, wrote extensively on it. With the dominance of functionalism through the middle years of the 20th century, the sociology of knowledge tended to remain on the periphery of mainstream sociological thought. It was largely reinvented and applied much more closely to everyday life in the 1960s, particularly by Peter L. Berger and Thomas Luckmann in "The Social Construction of Reality" (1966) and is still central for methods dealing with qualitative understanding of human society (compare "socially constructed reality"). The "archaeological" and "genealogical" studies of Michel Foucault are of considerable contemporary influence. The sociology of science involves the study of science as a social activity, especially dealing "with the social conditions and effects of science, and with the social structures and processes of scientific activity." Important theorists in the sociology of science include Robert K. Merton and Bruno Latour. These branches of sociology have contributed to the formation of science and technology studies. Both the ASA and the BSA have sections devoted to the subfield of Science, Knowledge and Technology. The ISA maintains a Research Committee on Science and Technology. Sociology of leisure is the study of how humans organize their free time. Leisure includes a broad array of activities, such as sport, tourism, and the playing of games. The sociology of leisure is closely tied to the sociology of work, as each explores a different side of the work–leisure relationship. More recent studies in the field move away from the work–leisure relationship and focus on the relation between leisure and culture. This area of sociology began with Thorstein Veblen's "Theory of the Leisure Class". This subfield of sociology studies, broadly, the dynamics of war, conflict resolution, peace movements, war refugees, conflict resolution and military institutions. As a subset of this subfield, military sociology aims towards the systematic study of the military as a social group rather than as an organization.