...Mr. Reilly starts at the beginning, “before philosophy discovered the order of nature and the role of reason,” “before the book of Genesis,” before Athens produced the great philosophers, particularly Aristotle and Socrates, who are his foundations for developing natural law. Before them, tribes, city-states, and empires were cosmological, uniform, habitual, making no distinctions socially between secular and sacred, nesting all values in the social order. Individuals thought communally, not considering themselves independent of their culture. Indeed, nothing was outside, including the gods of the cities and empires, by which communities defined all reality.
...Aristotle further rationalized this natural order with a first cause and the nature of ensuing causes, effects and ends, where all “nature ever seeks an end” and “does nothing without purpose or uselessly.” The end state is “the reason for what it is.”...
...Israel likewise broke from cosmological uniformity when revelation came from a single God who was prior to and outside nature and who commanded humanity to follow certain laws but allowed freedom to disobey. Thus, God even bound Himself as well as his people by a covenant between them. The Greek idea of first cause evolved into one of a personal and loving God who cared about his creatures and established rules derived from an objective natural moral law that, if heeded, would lead to spiritual fulfillment.
...European Christianity created an order that attempted to harmonize Greek rationalism and Jewish revelation, that over time produced an even more sophisticated medieval natural law rationalism, culminating in the works of Thomas Aquinas and the relative prosperity, limits, and order of the high Middle Ages.
Indeed, medieval universities so emphasized rationalism that reason itself turned against the Christian order; William of Ockham even undermined the fundamental natural law idea of essences. Rather than essences of reality with set moral ends, Platonic ideals were merely names we apply to them. Rather than having rational essences of unchanging natural laws set by God, He could change ends as He willed—an idea which abandons the certainty of reason and natural law for mere probability. Luther made the ultimate step against natural law with the belief that only faith mattered, which undermined the tenants of reason that had justified a European order developed over centuries. The result was many opposing moral justifications, the wars of religion, the end of Christendom, and the rise of the European Divine Right of Kings.
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