Logic 

Melvyn Bragg tackles the philosophy of logic - first mapped out by Aristotle in the 4th century BC; disregarded by Descartes in the 17th century and revived and reworked by Gottlob Frege in the 19th century; logic is at the heart of computer science and is a mathematical as well as a philosophical discipline. Melvyn is joined by A.C. Grayling, Professor of Philosophy at Birkbeck, University of London; Peter Millican, Gilbert Ryle Fellow in Philosophy at Hertford College at the University of Oxford; and Rosanna Keefe, Senior Lecturer in Philosophy at the University of Sheffield.