World 5 and medical knowledge.

What follows is a brief comment on Ludwik Fleck's paper on the foundations of medical knowledge translated by Thaddeus J. Trenn in this issue. Since the original is much older than I am, I have some scruples in presenting the critical thoughts which occurred to me when I read it a few years ago. Despite the criticism, I am very sympathetic to most of what Fleck has told us in his tragically neglected work. Two facts make Fleck's tragedy even more disturbing: (i) others have given rise to post-Fleck revolutions in epistemology by exploring his ideas while omitting proper references to him, and (ii) sociology of science, precisely what Fleck wanted to promote, has emerged without his work being operative in any sense. In my commentary, I shall examine his concept of social conditioning of knowledge.