6 Introduction. 



of ideas, but by philosophical reflection. Trained in the phi- 

 losophy which flourished in Italy in the 16th century, deeply 

 imbued with the doctrines of Aristotle, and practised in all 

 subtleties of the schools, Cesalpino was not the man to surren- 

 der himself quietly to the influence of nature on the unconscious 

 powers of the mind ; on the contrary, he sought from the first 

 to bring all that he learnt from the writings of others and from 

 his own acute observation of the forms of plants into subjection 

 to his own understanding. Hence he approached the task of 

 the scientific botanist in an entirely different way from that of 

 de l'Obel and Kaspar Bauhin. It was by philosophical reflec- 

 tions on the nature of the plant and on the substantial and 

 accidental value of its parts, according to Aristotelian concep- 

 tions, that he was led to distribute the vegetable kingdom into 

 groups and sub-groups founded on definite marks. 



This difference in the origin of the systematic efforts of 

 Cesalpino on the one hand and of de l'Obel and Bauhin on the 

 other is unmistakably apparent ; the Germans were instinc- 

 tively led by the resemblances to the conception of natural 

 groups, Cesalpino on the contrary framed his groups on the 

 sharp distinctions which resulted from the application of pre- 

 determined marks ; all the faults in Bauhin's system are due 

 to incorrect judgment of resemblances, those of Cesalpino to 

 incorrectness in distinguishing. 



But the main point of difference lies in the fact, that the 

 system is presented by de l'Obel and Bauhin without any state- 

 ment of the principles on which it rests ; in their account of it 

 the association of ideas is left to perfect itself in the mind of 

 the reader, as it grew up before in the authors themselves. 

 De l'Obel and Bauhin are like artists, who convey their own 

 impressions to others not by words and descriptions, but 

 by pictorial representations ; Cesalpino, on the other hand, 

 addresses himself at once to the understanding of his reader 

 and shows him on philosophic grounds that there must 

 be a classification, and states the principles of this classifi- 



