The major shift in recent years in the literatures about science is from the view of science as the knowledge that an individual possesses, to the view of science as a social institution. Different social philosophies judge science as a social phenomenon differently. In particular, the social philosophy that deems society a mere collection of individuals — reductionist individualism or psychologism — will make the least of the recent shift, whereas the social philosophy that deems people mere members of society — reductionist sociologism or organicism or holism — will make the most of it. Without elaborating on this, we may note that both of these extremes play down interpersonal interaction. The various interac­tionist schools should make the most of it, but one need not be a member of any of these schools to appreciate interpersonal interaction. Indeed, Popper has stressed this as early as in 1935. How does the recognition of the presence and importance of scientific interaction alter our view of science?