Critical political debate requires respect for principles of logic, rationality and reasonableness, as well as shared conceptions of evidence and relevance in the political arena. The author presents case studies in order to demonstrate the inherent dangers of not applying principles of reasoning to the interpretation of political events. Relevance and the adequacy of evidence are too often overlooked in favour of rhetoric and moral platitude, sometimes leading to deceit and always to ambiguity, to the detriment of democratic society. He investigates the US Bill of Rights in the context of...