OF NATURAL PHILOSOPHY. 143 



blance of several others, which at once decides 

 us in considering them as having a natural relation. 

 In the former cases, our ingenuity is exercised to de- 

 termine what can be the cause of their resemblance, 

 in the latter, of their difference ; the former belong 

 to the province of inductive generalization, and 

 afford the most instructive cases for the investiga- 

 tion of causes; the latter appertain to the more 

 secret recesses of nature; the very existence of such 

 families being in itself one of the great and compli- 

 cated phenomena of the universe, which we cannot 

 hope to unriddle without an intimate and extensive 

 acquaintance with the highest laws.* 



* The following passage, from Lindley's Synopsis of the 

 British Flora, characterises justly the respective merits, 

 in a philosophical point of view, of natural and artificial 

 systems of classification in general, though limited in its 

 expression to his own immediate science : " After all that 

 has been effected, or is likely to be accomplished hereafter, 

 there will always be more difficulty in acquiring a knowledge 

 of the natural system of botany than of the Linnamn. The 

 .atter skims only the surface of things, and leaves the student 

 in the fancied possession of a sort of information which it is 

 easy enough to obtain, but which is of little value when ac- 

 quired : the former requires a minute investigation of every 

 part and every property known to exist in plants ; but when 

 understood has conveyed to the mind a store of real inform- 

 ation, of the utmost use to man in every station of life. What- 

 ever the difficulties may be of becoming acquainted with plants 

 according to this method, they are inseparable from botany, 

 which cannot be usefully studied without encountering them." 

 Schiller has some beautiful lines on this, entitled " Mensch- 

 liches Wissen " (or Human Knowledge) ; Gedichte, vol. i. 

 p. 72. Leipzig, 1800. 



