This concise and accessible book is a synthesis of the basic principles of the contemporary realistic neopragmatist philosophy of science. It discusses the aim of basic science, the methods of scientific discovery, the criteria for scientific criticism, and the nature of scientific explanation. Included is a description of a newly emergent specialty called computational philosophy of science, in which computerized discovery systems create and test new scientific theories. It also examines the essentials of the underlying realistic neopragmatist philosophy of language that has made philosophy of science a coherent and analytical discipline, and that has given new meaning to such key terms as "theory", "observation" and "explanation".