World 3. Ontological and Epistemological Studies

Karl Popper introduced in 1967 his ontological doctrine of World 3, or 'the objective contents of thought'. His somewhat sketchy proposal provoked accusations of contradictions, objective idealism, and ontological extravagance, while some philosophers urged that the whole reality is socially constructed. This book presents a critical defence of Popper’s tripartite ontology as a form of emergent materialism. The physical World 1 has historical and systematic primacy over the mental World 2 and the cultural World 3. Human mind, the self, culture, and society are complex products of biological and cultural evolution, created and reproduced by the humankind. This ontological theory avoids the implausible aspects of reductive materialism and helps to understand the peculiar objective or 'supraindividual' character of cultural formations without idealist, Platonist, or supernaturalist assumptions.The eleven chapters of this work illustrate the interplay and reality of Popper’s three worlds. The examples of human-made World 3 entities include material artefacts (e.g. tools, toys, books, works of art) with cultural properties (e.g. information, meaning, price, value), abstract objects (e.g. mathematical entities, concepts, propositions, theories), social institutions (societies, rules, values, norms of language and law). Popper’s 'epistemology without a knowing subject' is replaced with Charles Peirce’s fallibilism, where the collective subject of scientific knowledge is the scientific community.      Ilkka Niiniluoto is Professor Emeritus of Theoretical Philosophy at the University of Helsinki. After Ph.D. on Jaakko Hintikka’s inductive logic in 1973, his main work has been in the explication of the notions of truthlikeness and scientific progress to defend critical scientific realism.