Natural law is the idea that there is an objective moral order, grounded in essential humanity, that holds universal and permanent implications for the ways we should conduct ourselves as free and responsible human beings. These 24 in-depth lectures consider the arguments for natural law, the serious objections that have been raised against it, and the ways, despite all overt criticisms, it remains a vital and even pervasive force in political, moral, and social life today, even while traveling under another name. Shaping Father Koterski's historical treatment is an appreciation of just how much thought, effort, and brilliance went into formulating and defending the crucial insights of natural law theory. Among other things, you'll look at: the virtual dialogue that took place between the Ionian scientists, the Sophists, and their great interlocutors, Socrates, Plato, and Aristotle; Thomas Aquainas's Summa Theologica , which sets out the account of natural law as that type of law through which humans take part according to their nature as free, intelligent, and responsible beings; the ways, by the American Founders' design, natural law thinking is poured into the foundations of our republican experiment in ordered liberty and constitutional democracy; and the criticisms leveled against natural law by Descartes, Rousseau, and Kant. Finally, Father Koterski asks whether modern evolutionary biology can claim to have discovered truths about human nature that render natural law theory unintelligible, whether the findings of anthropological research undercut natural law, and whether accepting the idea of natural law means accepting the existence of God and vice versa.