I think, there is not a general definition of necessary and sufficient conditions of a school in science. Szaki (1981:18-25) wrote about four meanings of the school concept: - an institutional meaning: Members of a school articulate in an institutional arrangement; - a psychological meaning: Members of a school articulate the same theory= ; - a typological meaning: Theoreticans of science define a group of scientists as a school if they have the same method; - a national meaning: Members of a school work at the same place. Sometimes there are more conditions for the definition of a school in the literature. The following definitions are from Lindenlaub (1993:406) and Rieter (2002:145): - one or more standard publications; - a written agenda of the school; - journals or other publications from the school; - a scientific association; - many pupils; - a chief schoolmaster. In an other definition by Pearson (1999:557) a school practices kuhnian 'normal science'. Literature: Lindenlaub, David F. (1993): The Myth of the Older Historical School of Economics, in: Central European History 26, pp. 405-416. Pearson, Heath (1999): Was There Really a German Historical School of Economics?, in: History of Political Economy 31, pp. 547-562. Rieter, Heinz (2002): Historische Schulen, in: Issing, Otmar (ed.): Geschichte der National=F6konomie, 4. revised edition, M=FCnchen. pp. 131= -168. Szacki, Jerzy (1981): "Schulen" in der Soziologie, in: Lepenies, Wolf (ed.): Geschichte der Soziologie, Studien zur kognitiven, sozialen und historischen Identit=E4t einer Disziplin, Vol. 2, Frankfurt/ Main, pp. 16= -30. Jan Pieter Schulz