A theory, writes Anthony Wilden, like any other adaptive system, must have a survival value. It is impossible, he continues, ‘for a theory not to have a referent or a goal outside itself, since “pure truth” not only does not exist, it has no survival value whatsoever.’ Wilden's reference to the ‘external’ goal of a theory suggests that theories carry subliminal messages which exceed the strict boundary of their textual content. An effective technique for identifying the political and normative undertones communicated by theories is an inquiry into those areas which supposedly of peripheral significance to them.