v.] 0alu* rrf ftatural f isforg Stmttcs. S3 



must aspire knowing, as he does, that classification by 

 type is simply an acknowledgment of ignorance and a 

 temporary device. 



So much in the way of negative argument as against 

 the reputed differences between Biological and other 

 methods. No such differences, I believe, really exist. 

 The subject-matter of Biological science is different 

 from that of other sciences, but the methods of all are 

 identical ; and these methods are 



1. Observation of facts including under this head 

 that artificial observation which is called experiment. 



2. That process of tying up similar facts into bundles, 

 ticketed and ready for use, which is called Comparison 

 and Classification, the results of the process, the 

 ticketed bundles, being named General propositions. 



3. Deduction, which takes us from the general pro- 

 position to facts again teaches us, if I may so say, to 

 anticipate from the ticket what is inside the bundle. 

 And finally 



4. Verification, which is the process of ascertaining 

 whether, in point of fact, our anticipation is a correct 

 one. 



Such are the methods of all science whatsoever ; but 

 perhaps you will permit me to give you an illustration 

 of their employment in the science of Life ; and I will 

 take as a special case, the establishment of the doctrine 

 of the Circulation of the Blood. 



In this case, simple observation yields us a knowledge 

 of the existence of the blood from some accidental 

 haemorrhage, we will say : we may even grant that it 

 informs us of the localization of this blood in particular 

 vessels, the heart, &c., from some accidental cut or the 

 like. It teaches also the existence of a pulse m various 

 parts of the body, and acquaints us with the structure of 

 the heart and vessels. 



c2 



