The Critique of Pure Reason, published by Immanuel Kant in 1781, is one of the most complex structures and the most significant of modern philosophy, bringing a revolution at least as great as that of Descartes and his Discourse on Method. The complexity of the first review (the second is the critique of practical reason, and the third is a critique of the faculty of judging), is such that Kant himself published an introductory text, entitled Prolegomena to Any Future Metaphysics. The aim of this book is summed up quite easily, however: metaphysics is a battle that needs to be ordered. Kant...