This anthology represents a collection of key research papers covering the areas of schema theory, concepts, induction, judgements under uncertainty, analogical reasoning and deductive thinking. The aim of the book is to present the reader with the seminal research into cognitive functioning through papers focusing upon cognitive representation and reasoning. Papers proposing relatively rigid cognitive representations are contrasted with research suggesting that these representations are more flexible - constructed as and when required, dependent upon the context. Similarly, research demonstrating the apparent systematic biases in human heuristic reasoning are contrasted with logic-based models of human reasoning.