INTRODUCTION xlix 



have been considerably earlier than the date of publica- 

 tion of the whole work, he did not know of Seneca's Q.N., 

 then the inference seems inevitable that there were current 

 a collection or collections of the opinions (Sogai) of the 

 older philosophers which were common property to any 

 one interested in such matters. The Placita attributed to 

 Plutarch, though its present form may be much later than 

 Pliny's time, may have been derived from sources of this 

 kind. We shall not be far wrong in supposing that, in 

 addition to the works still extant, there was a mass of 

 material available to Seneca and Pliny alike which repre- 

 sented the traditional views on physical and allied subjects 

 handed down from the old Greek philosophy. Most of 

 the Latin authors, seventeen in number in all, cited by 

 Pliny on Book II. are now known to us only by name ; 

 of those whose works remain, Varro is the only one whom 

 we should consider likely to furnish much material for the 

 topic in hand. 



Of Pliny's lists in general it may be said that they 

 indicate that a good many writers even among the 

 Romans had been attracted by subjects of a scientific or 

 quasi-scientific character, if we may not venture to say that 

 their works can rank as science even in the modified sense 

 in which the term is applicable to Seneca or Pliny. It is 

 in keeping with the character of the people that practical 

 sciences like agriculture (Varro, Columella) and architecture 

 (Vitruvius), not to mention cookery, should have received 

 special attention. These authors, with others like Manilius 

 (Astronomicd} and Pomponius Mela (geography), however 

 interesting in themselves, have only an indirect and some- 

 times only a remote bearing on the Physical Science of 

 their day. 



VI. THE "QUAESTIONES NATURALES" IN THE 

 MIDDLE AGES 



The Q.N. is a landmark in the progress of Physical 

 Science. From Aristotle and Theophrastus there is a 

 great gap until we reach Seneca : the gap is still greater 



