ABSTRACT
Anti-realism about the physical world is an occupational hazard of philosophy. The defence of realism depends on distinguishing it from other doctrines and on choosing the right place to start the argument. And the defence of that choice depends on naturalism. This chapter explores what realism is, distinguishing it from semantic doctrines with which it is often confused. It considers the arguments for and against realism about observables. The chapter also considers the arguments for and against realism about unobservables, 'scientific' realism. Many contemporary anti-realisms combine Kantianism with relativism to yield what is known as 'constructivism'. Kant was no relativist: the concepts imposed to constitute the known world were common to all mankind. The argument for scientific realism, realism about the unobservables of science, starts by assuming common-sense realism. And, setting aside some deep and difficult problems in quantum theory, the issue is over the existence dimension, over whether these unobservables exist.
