What was it that enabled Themistocles to win this decisive victory for Greece after disastrous defeats on land? Simply his skill in the politics of Athens. Themistocles was a Hellenic imperialist. He was opposed by Aristides, who was a very just man, and an anti-imperialist and "mugwump." Greece was at that time terribly menaced by the Persian power, and threatened with "Medization," or absorption into the Persian nationality. Themistocles saw that the country's only chance lay in a union of all the Hellenes, and in the construction of a navy worth the name. Aristides was a better orator than he, and at first won against him in the Athenian elections. The Greek spirit was innately hostile to anything like centralization or imperialism. But when Ægina, which was the leading Grecian maritime state, and had some good ships, turned against Athens and defeated it on the sea, the Athenians' eyes began to open. Themistocles pushed his plan for the construction of a fleet of two hundred vessels and the addition of twenty new ships every year to this navy. Squarely across his path stood Aristides, with his ridicule of the attempt of little Athens to become a maritime power, and his warnings against militarism. But Themistocles, by adroit politics, led the Athenians to become sick of Aristides, and persuaded them to ostracize or banish this just man. Aristides went to Ægina. Then Themistocles rushed forward his plan of naval reform, and carried it through. The two hundred ships were built, and not a moment too soon. It was this fleet, brilliantly led by Themistocles and Eurybiades at Salamis, which entangled the Persians in the narrow waters of Salamis and defeated them, and saved Europe for the Europeans. The victory saved it also for Christ, by keeping alive the worship of the half-gods of Greece and Rome until a whole-god came from Judæa. The Persians, too, had a whole-god. Idea for idea, principle for principle, tenet for tenet, dream for dream, all of later Judaism and all of medieval Christianity, except the person and story of Jesus, was in the religion of Persia. Not only the central ideas of formal Christianity, but many of its dependent and related principles, are found in Mithraism, which was the translation of the fundamental philosophic ideas of Zoroastrianism into terms of human life. The parallel is so striking that many thinkers regard Christianity merely as Mithraism bodied forth in a story invented by, or at least told to and believed by, a circle of primitive and uneducated zealots who knew nothing of the history of the doctrines they were embracing.