This book collects most of the invited papers presented at the 12thInternational Congress of Logic, Methodology and Philosophy of Sciencein Oviedo, August 2003. It contains state of the art accounts of ongoingwork by a selection of the most renowned researchers in the field. Thepapers in the Logic section deal with topics in mathematical logic, aswell as philosophical logic, and the area of logic and computation. Thesection on General Methodology contains articles on models, theories,probability, induction, causation, and other topics. A number of papersdiscuss Philosophical Issues of Particular Sciences, such asmathematics, physics, linguistics, psychology, biology, and medicine.There is also a section on Ethics of Science, and papers from a specialsymposium on the Emergence of Scientific Medicine in the 19th-20th Century.