52 SKETCH OF THE LIFE AND ACHIEVEMENTS 



southward to Opliir and the tropical gold re- 

 gions, and in western direction beyond the 

 Pillars of Hercules into the ocean; 2. The 

 Macedonian campaign under Alexander ; 3 . 

 The age of the Lagides, of Alexandria ; and 

 4. The great Eoman empire. Humboldt recog- 

 nized another powerful influence in the invasion 

 of the Arabs, who introduced a foreign element 

 into European civilization ; and further, the dis- 

 coveries of the Portuguese and Spaniards six or 

 seven centuries afterwards. These events gave 

 a characteristic impulse to the advancement of 

 physical and mathematical science, to geography 

 and astronomy. "From that period on," said 

 Baron Humboldt, " the spread of cosmical 

 science no longer depended on isolated political 

 events." 



The Arabs, a Semitic primitive tribe, not only 

 opposed barbarity, but re-opened the sources of 

 Greek philosophy, and new roads to civilization. 

 Humboldt, who showed in such a genial man- 

 ner that the destiny of peoples, independent of 

 their intellectual capacities, is also in a great 

 measure determined by a variety of external 

 conditions, the soil, the climate, and their rela- 

 tive distance from the seas, recognizes further- 

 more, in the peculiar form of the Arabian 

 peninsula, an important cause of the great 



