In Leviathan, Hobbes assumes a rational, skeptical style that shows the influence of the Enlightenment, sometimes called the “Age of Reason,” on his thinking. Hobbes’s rational approach can be seen in his treatment of supernatural phenomena as mere superstition. Discussing Marcus Brutus, the most famous of the assassins of Julius Caesar, Hobbes writes:
For he that taketh pains, and industriously layes himself to sleep, in case any uncouth and exorbitant fancy come unto him, cannot easily think it other than a Dream. We read of Marcus Brutus, (one that had his life given him by Julius Cæsar, and was also his favorite, and notwithstanding murthered him,) how at Philippi, the night before he gave battell to Augustus Cæsar, hee saw a fearfull apparition, which is commonly related by Historians as a Vision: but considering the circumstances, one may easily judge to have been but a short Dream.
Hobbes notes that classical historians—including Plutarch—believed that Brutus saw a “fearfull apparition” or ghost prior to the fateful battle of Philippi, and that more modern historians have uncritically repeated this implausible tale. In fact, Brutus’s encounter with a ghost is one of the most famous scenes in Shakespeare’s play Julius Caesar. However, Hobbes argues that there is a rational explanation for this seemingly supernatural phenomenon: Brutus had a “short dream” reflecting his feelings of guilt over his involvement in the assassination of Caesar. This is just one of many instances in Leviathan in which Hobbes uses reason to critique what he considers to be superstition.