Brian McGuinness is now Professor of the History of Philosophy at Siena. Past publications include the translation of Wittgenstein's Tractatus Logico-Philosophicus (with David Pears) and A Life of Wittegenstein (Volume 1, Young Ludwig, 1988). George Henrik von Wright was a pupil and friend of Wittgenstein and succeeded him as Professor of Philosophy at Cambridge. He has since been President of the National Academy in his native Finland. He is one of the trustees to the Wittgenstein estate, and responsible for many of the posthumous publications of Wittgensteins writings.