The next Bryan Magee discussion is about two philosophers who took Descartes’ Rationalism further and both proposed solutions to the problem of linking mind and matter: Spinoza and Leibnitz.  There are programmes in the In Our Time series on Spinoza and Leibnitz, but the latter focuses on the argument between him and Newton over who invented calculus.  Leibnitz' view that this was “The Best of All Possible Worlds” was lampooned by Voltaire in Candide.