The essays in this volume represent an approach to human knowledge that has had a profound influence on many recent thinkers. Popper breaks with a traditional commonsense theory of knowledge that can be traced back to Aristotle. A realist and fallibilist, he argues closely and in simple language that scientific knowledge, once stated in human language, is no longer part of ourselves but a separate entity that grows through critical selection.

In a paper ‘Is it True What They Say About Tarski?’, Dr Susan Haack explicitly denies the truth of an implicit assertion of mine, by writing ‘… Tarski does not present his theory as a correspondence theory’. My reply is to quote two brief passages from Tarski's work.