Matthew Stewart’s The Courtier and the Heretic is about Leibniz (the courtier) and Spinoza (the heretic). It is a superb introduction to their ideas and also an exciting story. As Liesl Schillinger put it in Great Minds Don’t Think Alike, a book review in the New York Times, “With ‘The Courtier and the Heretic,’ Stewart has achieved a near impossibility, creating a page-turner about jousting metaphysical ideas that casts the hallowed, hoary thinkers as warriors in a heated ideological battle.” This book review, along with Mad, bad and dangerous to know – it can only be a philosopher and Of miracles and monads, will give you a good idea of Stewart’s book and of Spinoza’s and Leibniz’s ideas.