20 ZOOLOGICAL PHILOSOPHY 



in natural science. When the interest of studying and knowing 

 nature was first felt, these artificial devices continued to be of assist- 

 ance in the prosecution of that study. These same artificial devices 

 have therefore an indispensable utility, not only for helping us to a 

 knowledge of special objects, but for facilitating study and the pro- 

 gress of natural science, and for enabling us to find our way about 

 among the enormous quantity of different objects that we have to 

 deal with. 



Now the philosophic interest embodied by the sciences in question, 

 although less widespread than that which relates to our economic 

 requirements, compels us to separate what belongs to artifice from 

 what is the sphere of nature. We have to confine within reason- 

 able hmits the consideration due to the first set of objects, and attach 

 to the second all the importance that they deserve. 



The artificial devices in natural science are as follows : 



(1) Schematic classifications, both general and special. 



(2) Classes. 



(3) Orders. 



(4) Families. 



(5) Genera. 



(6) The nomenclature of various groups of individual objects. 

 These six kinds of devices, commonly used in natural science, are 



purely artificial aids which we have to use in the arrangement and 

 division of the various observed natural productions ; to put us in 

 the way of studying, comparing, recognising and citing them. Nature 

 has made nothing of this kind : and instead of deceiving ourselves 

 into confusing our works with hers, we should recognise that classes, 

 orders, families, genera and nomenclatures are weapons of our own 

 invention. We could not do without them, but we must use them 

 with discretion and determine them in accordance with settled 

 principles, in order to avoid arbitrary changes which destroy all the 

 advantages they bestow. 



It was no doubt indispensable to break up the productions of nature 

 into groups, and to establish different kinds of divisions among them, 

 such as classes, orders, families and genera. It was, moreover, necessary 

 to fix what are called species, and to assign special names to these 

 various sorts of objects. This is required on account of the limitations 

 of our faculties ; some such means are necessary for helping us to fix 

 the knowledge which we gain from that prodigious multitude of 

 natural bodies which we can observe in their infinite diversity. 



But these groupings, of which several have been so happily drawn 

 up by naturalists, are altogether artificial, as also are the divisions 

 and sub-divisions which they present. Let me repeat that nothing 



