Austrian-born English philosopher Ludwig Wittgenstein (1889–1951) is considered as one of the most influential although controversial thinkers of the 20th century. His work touched on topics such as ethics, logic, and language. Rom Harré is Distinguished Research Professor in the Department of Psychology at Georgetown University and Emeritus...

  Thanks to his groundbreaking work in logic, the philosophy of mind, mathematics, and language, as well as two published works, Tractatus and Philosophical Investigations, Ludwig Wittgenstein (1889-1951) played a leading role in the 20th-century analytic philosophy. Jaakko Hintikka was Professor of Philosophy at Boston University. Author of over...