`This is a remarkable book... it covers an awesome amount of ground. It tells us in some detail what cognitivists, social constructionists, discourse analysts, argumentation theorists, conversation analysts and others have to contribute to our understanding of explanation, reasoning, argument, excuses and justification... It is remarkable also for the clarity of its exposition, which is such as to command this reader's unqualified admiration and gratitude. The style is disarmingly unpretentious, even playful.