FITNESS AND ADAPTATION 75 



ment. This response is expressed in constructive, co- 

 operative actions, and may be measured in these actions 

 only. That is, in the relative change of form and posi- 

 tion of various parts, and in the architecture and move- 

 ments of the whole organism from one time, or place, 

 to another. 



These constructive actions of the physical and or- 

 ganic world constitute the currents and counter cur- 

 rents of nature's perpetual flux. Science has no means 

 of measuring them except in terms of themselves, for 

 there is no absolute standard of value, either for direc- 

 tion, length of time, or extension in space. The north 

 star, the radius of the earth, or the revolution of the 

 earth in its orbit, which we use as our standards of 

 measurement, are themselves the expression of chang- 

 ing action in things already constructed. 

 . The terms commonly used to indicate these con- 

 structive processes and their opposites are good and 

 evil. These terms are rarely used by scientists in their 

 more formal discussions, nevertheless no other terms 

 can quite fill their places. Substitute terms either 

 mean precisely the same thing, or conceal beneath a 

 cumbersome, unfamiliar terminology the very idea the 

 scientist wishes to convey. 



When we say, for example, that something is good 

 or evil for an animal, all we mean is that it is more or 

 less constructive and preservative for that animal, jor 

 more or less destructive. So it is with all our measure- 

 ments, they always express in some way the degree of 

 constructive or destructive action, in positive or nega- 

 tive terms, in reference to that particular thing; that is, 

 in terms of good and evil. 



Thus in spite of the infinite variety of narure-ac- 



