The Jewish people had the advantage, from the captivity of Babylon up to the Middle Ages, of being in a state of the greatest tension.  This is why the interpreters of the spirit of the nation during this long period seemed to write under the action of an intense fever, which placed them constantly either above or below reason, rarely in its middle path.  Never did man seize the problem of the future and of his destiny with a more desperate courage, more determined to go to extremes.  Not separating the lot of humanity from that of their little race, the Jewish thinkers were the first who sought for a general theory of the progress of our species.  Greece, always confined within itself, and solely attentive to petty quarrels, has had admirable historians; but before the Roman epoch, it would be in vain to seek in her a general system of the philosophy of history, embracing all humanity.  The Jew, on the contrary, thanks to a kind of prophetic sense which renders the Semite at times marvellously apt to see the great lines of the future, has made history enter into religion.  Perhaps he owes a little of this spirit to Persia.  Persia, from an ancient period, conceived the history of the world as a series of evolutions, over each of which a prophet presided.  Each prophet had his hazar, or reign of a thousand years (chiliasm), and from these successive ages, analogous to the Avataer of India, is composed the course of events which prepared the reign of Ormuzd.  At the end of the time when the cycle of chiliasms shall be exhausted, the complete paradise will come.  Men then will live happy; the earth will be as one plain; there will be only one language, one law, and one government for all.  But this advent will be preceded by terrible calamities.  Dahak (the Satan of Persia) will break his chains and fall upon the world.  Two prophets will come to console mankind, and to prepare the great advent.[1] These ideas ran through the world, and penetrated even to Rome, where they inspired a cycle of prophetic poems, of which the fundamental ideas were the division of the history of humanity into periods, the succession of the gods corresponding to these periods—­a complete renovation of the world, and the final advent of a golden age.[2] The book of Daniel, the book of Enoch, and certain parts of the Sibylline books,[3] are the Jewish expression of the same theory.  These thoughts were certainly far from being shared by all; they were only embraced at first by a few persons of lively imagination, who were inclined toward strange doctrines.  The dry and narrow author of the book of Esther never thought of the rest of the world except to despise it, and to wish it evil.[4] The disabused epicurean who wrote Ecclesiastes, thought so little of the future, that he considered it even useless to labor for his children; in the eyes of this egotistical celibate, the highest stroke of wisdom was to use his fortune for his own enjoyment.[5] But the great achievements of a people are generally wrought