Formal and informal fallacies in anaesthesia

Formal and informal fallacies refer to errors in reasoning or logic, which result from invalid arguments. Formal fallacies refer to arguments that have an invalid structure or 'form', while informal fallacies refer to arguments that have incorrect or irrelevant premises. There are many formal and informal fallacies that could theoretically occur in anaesthesia practice or in the appraisal of anaesthesia research. This paper describes several such potential fallacies. It is possible that a greater awareness, recognition and discussion of these logic-based errors will lead to improved patient safety and more informed appraisal of clinical research.