A set of basic assumptions appears to underlie much current research and teaching using systems thinking. But although these assumptions are frequently deployed to support theories, arguments and debate, it is difficult to detect or establish the empirical evidence or observations that justify them. This lack of evidence is worrying. As Burrell and Morgan (1979) point out, "In order to understand alternative points of view it is important that a theorist be fully aware of the assumptions upon which his own perspective is based."