The Legal Theory Bookworm recommends Lectures on the History of Moral and Political Philosophy by G.A. Cohen. Here is a description:
G. A. Cohen was one of the leading political philosophers of recent times. He first came to wide attention in 1978 with the prize-winning book Karl Marx's Theory of History: A Defence. In subsequent decades his published writings largely turned away from the history of philosophy, focusing instead on equality, freedom, and justice. However, throughout his career he regularly lectured on a wide range of moral and political philosophers of the past. This volume collects these previously unpublished lectures.
Starting with a chapter centered on Plato, but also discussing the pre-Socratics as well as Aristotle, the book moves to social contract theory as discussed by Hobbes, Locke, and Hume, and then continues with chapters on Kant, Hegel, and Nietzsche. The book also contains some previously published but uncollected papers on Marx, Hobbes, and Kant, among other figures. The collection concludes with a memoir of Cohen written by the volume editor, Jonathan Wolff, who was a student of Cohen's.
A hallmark of the lectures is Cohen's engagement with the thinkers he discusses. Rather than simply trying to render their thought accessible to the modern reader, he tests whether their arguments and positions are clear, sound, and free from contradiction. Throughout, he homes in on central issues and provides fresh approaches to the philosophers he examines. Ultimately, these lectures teach us not only about some of the great thinkers in the history of moral and political philosophy, but also about one of the great thinkers of our time: Cohen himself.
And from the reviews:
"This collection of lectures--erudite, demanding, and precise, yet funny and accessible--captures Jerry Cohen's inimitable voice and sparkling brilliance. Whether discussing Plato, Locke, Marx, or Nietzsche, dCohen guides the reader through the historical context while rejuvenating its urgency by interweaving modern political concepts. Cohen's rare approach--combining charitable interpretation, intellectual honesty, analytical clarity, and a love of teaching--exemplifies how to treat historical texts as contemporary interlocutors."--Seana Shiffrin, UCLA School of Law
"These essays demonstrate brilliantly Cohen's intellectual commitment to going naked into the debating chamber. Arguments are broken down, reconstructed, analyzed, and evaluated with such perspicuity that readers can pinpoint precisely where their own judgments diverge from Cohen's, while being challenged to match his standards in responding. It is a measure of the sharpness of Cohen's intellect that even the essay on Nietzsche, where his knowledge is most limited, offers insights and arguments of real merit."--David Owen, University of Southampton
"Jerry Cohen prepared his lectures with the same meticulous care as his published writing. This collection shows him engaging with some of the greatest thinkers of the past, scrutinizing their ideas and doing his best to formulate them to match his own high standards of clarity and precision. Those meeting Cohen here for the first time will encounter his unique voice: unrelenting in its pursuit of an argument but never petty or pedantic. It is a book from which we can all learn."--Michael Rosen, Harvard University