Abstract: This book gives a systematic formulation of critical scientific realism by surveying varieties of realism in ontology, semantics, epistemology, theory construction, and methodology. According to the standard version of scientific realism, scientific theories are attempts to give true descriptions of mind-independent and possibly unobservable reality, where truth means correspondence between language and reality. Critical realism adds to this view four important qualifications: our access to the world is always relative to a chosen linguistic framework (conceptual pluralism); all human knowledge about reality is uncertain and corrigible (fallibilism); even the best theories in science may fail to be true, but nevertheless, successful theories typically are close to the truth (truthlikeness); a part, but only a part, of reality consists of human-made constructions (Popper's world 3). Niiniluoto combines Tarski's semantic definition of truth with his own explication of Popper's notion of verisimilitude, and characterizes scientific progress in terms of increasing truthlikeness. He argues in detail that critical scientific realism can be successfully defended against its most important current alternatives: instrumentalism, constructive empiricism, Kantianism, pragmatism, internal realism, relativism, social constructivism, and epistemological anarchism.

Keywords: constructive empiricism, fallibilism, instrumentalism, Kantianism, philosophy of science, pragmatism, realism, scientific progress, scientific realism, scientific theory, theory construction, truth