The sixth volume of Copleston's history, and the last one I finished the first time I read these in college, so the last three will be for the first time. This volume covers the Enlightenment/Aufklärung (about 40% of the book, or part one in the old paperback edition which divided it into two books) with particular emphasis on Rousseau, and the philosophy of Kant (about 60%). The treatment of the Enlightenment was as fair as one could hope for from a Catholic priest who is obviously not sympathetic to their project, and the section of Kant was as clear as possible given that it was about Kant. When I read this the first time around, I hadn't yet read a lot of any of these philosophers, except Rousseau on the Social Contract and Kant's Prolegomena; since then I've read quite a bit, including Voltaire, Diderot, Lessing, most of Rousseau and all three of Kant's Critiques, as well as having taken a course that focused on the Critique of Pure Reason. The more I know about these figures the more impressed I am with Copleston's ability to summarize their positions. Otherwise, I won't repeat what I've said in my reviews of the first five books. No substitute for reading the actual philosophers, or even the more specialized secondary works, but still the best general history in English.