186 NOVUM ORGANUM 



for the operative branch, as we will mention in its proper 

 place when speaking of the practical deductions. 



XXXIII. In the eleventh rank of prerogative instances 

 we will place accompanying and hostile instances. These 

 are such as exhibit any body or concrete, where the required 

 nature is constantly found, as an inseparable companion, 

 or, on the contrary, where the required nature is constantly 

 avoided, and excluded from attendance, as an enemy. From 

 these instances may be formed certain and universal propo 

 sitions, either affirmative or negative; the subject of which 

 will be the concrete body, and the predicate the required 

 nature. For particular propositions are by no means fixed, 

 when the required nature is found to fluctuate and change 

 in the concrete, either approaching and acquired, or reced 

 ing and laid aside. Hence particular propositions have no 

 great prerogative, except in the case of migration, of which 

 we have spoken above. Yet such particular propositions 

 are of great use, when compared with the universal, as will 

 be mentioned in its proper place. Nor do we require abso 

 lute affirmation or negation, even in universal propositions, 

 for if the exceptions be singular or rare, it is sufficient for 

 our purpose. 



The use of accompanying instances is to narrow the 

 affirmative of form; for as it is narrowed by the migrating 

 instances, where the form must necessarily be something 

 communicated or destroyed by the act of migration, so it is 

 narrowed by accompanying instances, where the form must 

 necessarily be something which enters into the concretion 

 of the body, or, on the contrary, is repugnant to it; and 

 one who is well acquainted with the constitution or forma 

 tion of the body, will not be far from bringing to light the 

 form of the required nature. 



