After a critical summary and analysis of syllogistic, inductive, and modern symbolic logic, this book undertakes a study of the concepts, symbolism, and applications of what has become known as deontic logic, or the logic of obligation, particularly as it relates to moral and legal reasoning involved in the making of decisions, choices, and the performance of human actions. The meanings of the terms ‘act’ and ‘action’ are thoroughly discussed as are the terms ‘omission’ and ‘attempt’. Both dyadic and multi-valued versions of deontic logic and the insights of Lofti Zadeh’s ‘fuzzy logic’ are referenced throughout the book, specifically in the chapter on the Logic of Jokes. The aesthetics and ethics of reasoning in mathematics, physical science, and law are discussed as well as the notion of commitment.