According to Professor Lucke, Goodhart’s ’material facts’ theory of precedent is the best explanation of ratio decidendi yet proposed. However, ’material’ and ’facts’, as used by Goodhart, are fundamentally ambiguous. ’Facts’ should be taken to mean the actual facts of the precedent, to be applied to other cases by analogical reasoning (not ’classes of facts’, to be applied deductively), Professor Lucke argues. ’Material’ should be taken to mean ’important for the purpose of justifying the decision’ (not ’important for prescriptive purposes’). So clarified (or, perhaps, modified) Goodhart’s theory yields a realistic and adequate explanation of the binding force of precedent.