The process of inference is essential for everyday communication and understanding. It is also central to scientific reasoning and is the focus of research in many different areas, most recently in cognitive science. This up-to-date review of empirical and theoretical work on reasoning and linguistic inference will be a useful introduction for students of language and thought. Focusing on the relationship between what people do and what, according to logic, people are supposed to do when making inferences, the authors bring together the disciplines of psychology and philosophical logic. They explore the subtle link between the two perspectives to shed light on how inference is expected to work and how it works in reality. They extend their coverage to make links with the wider theoretical context, and show how their work has implications in areas such as the debates about human rationality, child development, evolutionary influences, and artificial versus human intelligence.