270 DEVELOPMENT AND PURPOSE CHAP. 



judgment is impressed on us by whatever experience or 

 processes of thought lead to its formation, and on the force 

 of other judgments which corroborate or conflict with it. 



So far we have supposed merely that the first judgment, 

 which we have called A, is necessitated by the second B, and 

 this leaves us with the alternatives of either seeking a 

 further ground for B or assuming its truth without proof. 

 But there is a further possibility. It may be that while B 

 necessitates A, it is equally true that A necessitates B. If 

 that is the case, we have a consilience of two independent 

 judgments, and the result is a miniature system in which the 

 several parts imply one another. In this system there is 

 no part without some rational justification. For if we 

 start with A we find it corroborated by B, and if with B we 

 find it corroborated by A. Of course, if we only believe A 

 because we believe B, and believe B only because of A, this 

 would be to argue in a circle. But if we believe each 

 independently on its own merits, and if they corroborate 

 one another, the case is altered. Starting from different 

 sides they meet in one point. The fact of their consilience 

 tends to substantiate both at once. Their respective con- 

 tents throw light on one another. We are no longer 

 proceeding in a linear series, proving one proposition by 

 means of another which is unproven and unexplained. 

 We are moving within a miniature system, each part of 

 which necessitates the other, and no part figures as an 

 absolute 'beginning,' nor does any necessarily point for 

 explanation to something outside the system. If this is so, 

 the system AB is a rational system devoid of that self- 

 mutilation which we found in the deductive c series.' 



As long as our conclusions depend wholly on premisses, 

 and these on further premisses, until we come back to first 

 principles, our reasoning forms a chain which hangs from a 

 fixed support. But the support itself is non-rational. No 

 reasoned account of it is or can be given, and no completely 

 rational system can therefore be formed on this method. 

 It is only when each element in a system necessitates and is 

 necessitated by the remainder that the non-rational element 

 disappears. Every judgment affirming some element in 

 such a system has a rational ground, and the same may be 



