THE SCIENCE OF HAPPINESS 



even here. Many a worker has been able to defy the 

 onslaughts of time still more effectively. Each of the 

 three great tragedians of Greece, ^Eschylus, Sophocles, 

 and Euripides, continued to write with undiminished 

 vigor and effectiveness till past threescore and ten; 

 and Sophocles produced the "(Edipus Colonus," 

 which ranks among his greatest works, when he was 

 more than eighty. Socrates seems to have been taken 

 off in his mental prime, though he also had com- 

 passed his threescore and ten years. Plato continued 

 to teach in his famous Academy till his death at eighty 

 and the comprehensive "Republic," the "Timaeus," 

 and the unfinished "Critias," are believed to have 

 been composed in his latest years. Herodotus was 

 probably hard upon sixty when he completed his 

 history. Thucydides, dying at seventy-five, left the 

 history of the Peloponnesian Wars unfinished. Taci- 

 tus, the greatest of Roman historians, was yet another 

 classical writer who made the world debtor to his 

 seventh decade. 



But it is not the classical world alone that can show 

 its lists of active septuagenarians. The most recent 

 generations can hold their own, in this regard, with the 

 great days of the past. Goethe, greatest master of the 

 Germanic tongue, finished " Faust," his master work, 

 on the eve of his eighty-third birthday. Alexander von 

 Humboldt wrote Cosmos, the crowning literary prod- 

 uct of his active life, during his last seventeen years, 

 completing it in his ninety-third year. As it is a work 

 summarizing the universal knowledge acquired in a 

 life-time of study, the time of its composition was most 



