So ends the Greek age of Faith. How strikingly does its history recall the corresponding period of individual life--the trusting spirit and the disappointment of youth. We enter on it full of confidence in things and men, never suspecting that the one may disappoint, the other deceive. Our early experiences, if considered at all, afford only matter of surprise that we could ever have been seriously occupied in such folly, or actuated by motives now seeming so inadequate. It never occurs to us that, in our present state, though the pursuits may have changed, they are none the less vain, the objects none the less delusive. The second age of Greek philosophy ended in sophism, the third in scepticism. Speculative philosophy strikes at last upon a limit which it can not overpass. This is its state even in our own times. It reverberates against the wall that confines it without the least chance of making its way through. CHAPTER VI. THE GREEK AGE OF REASON. RISE OF SCIENCE. THE MACEDONIAN CAMPAIGN.--_Disastrous in its political Effects to Greece, but ushering in the Age of Reason._ ARISTOTLE _founds the Inductive Philosophy.--His Method the Inverse of that of Plato.--Its great power.--In his own hands it fails for want of Knowledge, but is carried out by the Alexandrians._ ZENO.--_His Philosophical Aim is the Cultivation of Virtue and Knowledge.--He is in the Ethical Branch the Counterpart of Aristotle in the Physical._ FOUNDATION OF THE MUSEUM OF ALEXANDRIA.--_The great Libraries, Observatories, Botanical Gardens, Menageries, Dissecting Houses.--Its Effect on the rapid Development of exact Knowledge.--Influence of Euclid, Archimedes, Eratosthenes, Apollonius, Ptolemy, Hipparchus, on Geometry, Natural Philosophy, Astronomy, Chronology, Geography._ _Decline of the Greek Age of Reason._ [Sidenote: The Greek invasion of Persia.] The conquest of Persia by Alexander the Great is a most important event in European history. That adventurer, carrying out the intentions of his father Philip, commenced his attack with apparently very insignificant means, having, it is said, at the most, only thirty-four thousand infantry, four thousand cavalry, and seventy talents in money. The result of his expedition was the ruin of the Persian empire, and also the ruin of Greece. It was not without reason that his memory was cursed in his native country. Her life-blood was drained away by his successes. In view of the splendid fortunes to be made in Asia, Greece ceased to be the place for an enterprising man. To such an extent did military emigration go, that Greek recruits were settled all over the Persian empire; their number was sufficient to injure irreparably the country from which they had parted, but not sufficient to Hellenize the dense and antique populations among whom they had settled. [Sidenote: Its ruinous effect on Greece.]