It is desirable, however, to form some estimate of Pliny’s fitness for his task in order to judge how accurate a picture of ancient science his work is. He does not seem to have had much detailed training or experience in the natural sciences himself. He writes not as a naturalist who has observed widely and profoundly the phenomena and operations of nature, but as an omnivorous reader and voluminous note-taker who owes his knowledge largely to books or hearsay, although occasionally he says “I know” instead of “they say,” or gives the results of his own observation and experience. In the main he is not a scientist himself but only a historian of science or nature; after all, his title, _Natural History_, is a very fitting one. The question, of course, arises whether he has sufficient scientific training to evaluate properly the work of the past. Has he read the best authors, has he noted their best passages, has he understood their meaning? Does he repeat inferior theories and omit the correcter views of certain Alexandrian scientists? These questions are hard to answer. On his behalf it may be said that he deals little with abstruse scientific theory and mainly with simple substances and geographical places, matters in which it seems difficult for him to go far astray. Scientific specialists were not numerous in those days, anyway, and science had not yet so far advanced and ramified that one man might not hope to cover the entire field and do it substantial justice. Pliny the Younger was perhaps a partial judge, but he described the _Natural History_ as “a work remarkable for its comprehensiveness and erudition, and not less varied than Nature herself.”[129] [Sidenote: His use of authorities.]