... arrive at the new truth with hands bloodstained from the slaughter of a thousand platitudes. Ortega y Gasset, "Revolt of the Masses" The object of this article is to attempt to give a concise account of recent advances in our understanding of the underlying biochemical disorder in hepatolenticular degeneration, not to describe the clinical manifestations and the various diagnostic pitfalls to which these may give rise. In the light of this new knowledge reference can be made to the theories of pathogenesis and to progress in the treatment of the disease. Accounts of the clinical course of the illness have been given in recent review articles,1,2 and, of course, Wilson's original monograph 3 must be consulted by all interested in the condition. As in other rapidly advancing fields of knowledge, the literature on Wilson's disease contains contradictions and discrepancies which are hard to reconcile. Similarly, there are divergent theories