Methodology is a central issue in the theory and practise of information systems development. Structured methods, for instance, have been widely championed as providing a way of improving the quality of software systems. In this paper a case study is presented in which a mail order company made an attempt to implement a well-known methodology, Structured Systems Analysis and Design Methodology (SSADM). Far from facilitating the development process, SSADM encouraged a rigid and mechanical approach in which the methodology was applied in a ritualistic way which inhibited creative thinking. The argument is thus, that methodology, although its influence may be benign, has the potential to operate as a ‘social defence’, i.e. as a set of organizational rituals with the primary function of containing anxiety. The grandiose illusion of an all-powerful method allows practitioners to deny their feelings of impotence in the face of the daunting technical and political challenges of systems development. By withdrawing into this fantasy world the learning processes that are critical to the success of systems development are jeopardized. Methodology, whilst masquerading as the epitome of rationality, may thus operate as an irrational ritual, the enactment of which provides designers with a feeling of security and efficiency at the expense of real engagement with the task at hand.