Answer: The Roman government valued order and law.
Explanation: The central idea is that the Roman government valued order and law. The author indicates that Romans valued intelligence, but not as much as they valued order and law. The author points out the differences between Greek and Roman government values, but he does not indicate that one was superior. The author states that the Roman government maintained checks and balances, however, this is a specific detail, or example, rather than the overall central idea.