Step 1: Understanding the Question:
The question asks for the primary inspiration behind the classical Natural Law philosophy of the ancient Greeks.
Step 2: Key Concepts and Approach:
We need to examine ancient Greek philosophy (e.g., Socrates, Plato, Aristotle) and how they conceived of natural law.
Step 3: Detailed Explanation:
• Physis vs. Nomos: Greek philosophers distinguished between "physis" (nature) and "nomos" (man-made custom/law).
• Universal Morality: They argued that nature contains an objective, rational, and moral order that is discoverable by human reason. This order consists of universal moral principles.
• Socrates and Plato: Socrates believed that human-made laws should conform to absolute truths and virtues. Plato emphasized justice as a universal, ideal form.
• Aristotle: Aristotle, often considered the father of natural law, distinguished between natural justice (which has the same force everywhere) and conventional justice (which is man-made).
Step 4: Final Answer:
The classical natural law of the Greeks was inspired by universal moral principles. Therefore, Option A is correct.