Text: The situation stabilized with Vespasian, and the second century A.D. is often considered the golden age of the empire (Gibbon himself says that the time of Marcus Aurelius--late second century--was the best time to live of all in history).
Entailment: Gibbon thinks that the late second century was a great time to be alive.
Contradiction: The empire had never had a period of greatness, or golden age.