History, like an individual's life, is a succession of well-defined periods. Herodotus took as his subject a long cycle of events; the shorter period was first treated by Thucydides who introduced methods which entitle him to be regarded as the first modern historian. Born in Attica in 471 he was a victim of the great plague, was exiled for his failure to check Brasidas at Eion in 424 and spent the rest of his life in collecting materials for his great work. His death took place about 402. His preface is remarkable as outlining his creed. First he states his subject, the Peloponnesian war of 431-404; he then tests by an appeal to reason the statements in old legends and in Homer, arguing from analogy or from historical survivals in his own time to prove that various important movements were caused or checked by economic influence. He uses his imagination to prove that the importance of an event cannot be decided from the extant remains of its place of origin, for if only the ruins of both Sparta and Athens were left, Sparta would be thought to be insignificant and Athens would appear twice as powerful as she really is. Poetical exaggeration is easy and misleading, and ancient history is difficult to determine by absolute proofs. "Men accept statements about their own national past from one another without testing them." "To most men the search for truth implies no effort; they prefer to turn to the first accounts available." "It was difficult for me to write an exact narrative of the speeches actually made; I have therefore given the words that might have been expected of each speaker, adhering to the broad meaning of what was really uttered. The facts I have not taken from any chance person, nor have I given my own impressions, but have as accurately as possible written a detailed account of what I witnessed myself or heard from others. The discovery of these facts was laborious owing to conflicting statements and confused memories and party favour. Perhaps the unromantic nature of my record will make it uninteresting; but if any person will judge it useful because he desires to consider a clear account of actual facts and of what is likely to recur at some future time, I shall be content. As a compilation it is rather an eternal possession than a prize-essay for a moment." The essentially modern idea of history writing is here perfectly evident.