This paper concerns the strongly theory based organisational intervention - Stafford Beers' Viable Systems Diagnosis (VSD). The assumption that organisations have difficulty in transforming good theories into effective workplace practices is examined using VSD. We propose levels of knowledge or recursions of the Beer system that are appropriate and effective in terms of organisational interventions. We contend that the lexis emanating from Brain of the Firm, and The Heart of the Enterprise exacerbates the complexity of VSD causing readers to focus on Diagnosing the System. We suggest this outcome contributes to the non-popularity of VSD, but that Beer himself cannot be exonerated. The lack of fundamental VSD principles, identified as a deficiency in Diagnosing the System is expanded from the antecedents, Brain and Heart. The paper concludes by considering a systematic categorisation of Beer's work that will guide organizational change agents wishing to use this intellectually complex and powerful system
