DESCRIPTIVE SCIENCE 137 



chemical properties; nor would one expect to find light and 

 electrical phenomena to be grouped together, though modern 

 physics has shown that they are identical. Resemblances 

 such as these are revealed only in the more advanced stages 

 of the science, and through the application of highly com- 

 plicated techniques. For a purely descriptive science they 

 are non-existent. 



(3) Similar remarks apply to the serial properties of 

 events. It seems safe to say that recognition of order re- 

 quires greater abstraction than recognition of mere simi- 

 larities. Hence it is likely that a purely descriptive science 

 will contain only a minimum of ordered groups. Such as 

 are found will be based on obvious properties, like size, 

 shape, weight, motion, color, and sound. Most of these 

 sense qualities exhibit apparent variations in degree and 

 thus may be arranged in series. Where there are no obvious 

 differences in degree there are relations such as that of 

 "betweenness" which permit the establishment of ordered 

 groups. For example, green is quite obviously between 

 blue and yellow, yellow between green and orange, orange 

 between yellow and red, and so on; in this way the usual 

 spectrum arrangement of the colors becomes possible. Sim- 

 ilarly, a square is clearly between a triangle and a pen- 

 tagon, and a pentagon between a square and a hexagon; 

 in this way regular rectilinear figures may be arranged in 

 order. 



When the order of events is of a certain kind, measuring 

 techniques become applicable. Descriptive science does not 

 employ measuring operations unless it wishes to introduce 

 greater precision than is possible through the crude judg- 

 ments of sense perception. Man's unaided awareness enables 

 him to make relatively satisfactory judgments as to which 

 of two objects is larger, or heavier, or softer, or moving 

 faster. The techniques for such decisions are simple. Ob- 

 ject A is larger than object B if when the two coincide in 

 certain points certain other points of A extend beyond the 

 corresponding points of B; object L is heavier than object M 



