ISO DOGMATISM AND EVOLUTION 



of the limits of the particular interests and the particular occasion 

 which have called it forth. In what follows we shall devote our 

 attention more particularly to the latter aspect of the develop 

 ment, without, however, wholly disregarding the former. 



Let us note at the outset what is meant by the relativity of the 

 judgment to the particular occasion. An illustration may help 

 us here. Suppose that upon a piece of paper two geometrical 

 figures are drawn with considerable care. We call the one a 

 circle and the other a rectangle. Yet we are aware that a micro 

 scope would reveal irregularities of curvature in the first figure 

 and inexactness of angles in the second, and even that it would 

 taken an infinite amount of correction to make the first figure a 

 perfect cricle or the second a true rectangle. If we are to speak 

 accurately we should have to confess that the one figure exempli 

 fied circularity no more than the other; and, on the other hand, 

 that we could no more truly refer to the second as a rectangle 

 than to the first. But we could conform to accuracy in speaking, 

 only on the penalty of speaking only in negatives. If the concept 

 of the circle were only to be applied with mathematical exactness, 

 it could never be identified with any concrete phenomenon at all. 

 What determines the applicability of a concept in any particular 

 case may vary greatly We may be willing to accept a figure 

 as a circle only when the most accurate measurements obtainable 

 fail to carry the correction further, and when, although we may 

 on general principles feel sure that the figure must deviate from 

 circularity, we are unable to point out just how and to what de 

 gree it does so deviate. In the vast majority of cases, however, 

 the degree of accuracy which we demand is not determined by 

 the extreme limit of the finest instrument manufactured. Gen 

 erally we are satisfied with what looks round to the unassisted 

 eye; and often we do not stop to notice even palpable irregulari 

 ties. 



What makes the difference? The answer is obvious. It is 

 the exigency of the occasion. To speak of the inaccuracy of a 

 given judgment as negligible implies a reference to an end that 



