COMMON' SENSE (aXD SCIEXCe) 17 



line across a gorge the length of the available cordage is the factor 

 of primary concern; secondary attention may be given to weight and 

 strength, but the composition of the line is of no concern whatever. 

 The pilot of a plane laboring in a storm will feel a primary concern 

 for the weight of his cargo; its shape does not interest him, though its 

 value will cause him longer to defer jettisoning gold than sand. 



Ultimately, quality-concepts are adjectival, as when we speak of a 

 weighty object or a long rope. But, once recognized as useful, they 

 may be transmuted into nouns, like weight and length. Such a 

 "property of matter" is a characterization of something in relation 

 to a context of obser\'ation. If we take the context for granted, as in- 

 variable if not invariant, we may usefully regard the property as an 

 inherent quality of the something observed. Thus, setting out from 

 the conception of "moving bodies," we come ultimately to the study of 

 "motion" as such. Howe\'er, an element of danger always attends 

 such transmutation. Having rendered "loving" into "love," "honor- 

 able" into "honor," "thinking" into "thought" and even "mind," the 

 philosopher may entice us into pursuit of apparently meaningful but 

 utterly empty questions: e.g., what is the nature of that thing called 

 mind? The man of common sense himself often falls victim of this 

 misconception of adjectives as nouns. Even the scientist has not been 

 immune: e.g., the concept of light as an undulatory phenomenon 

 gives rise to the concept of a medium of undulations— the luminifer- 

 ous ether. 



The tool function of concepts. Concepts are not found as such in 

 nature; they are evoked in the human mind hij nature. Experience 

 cannot warrant concepts "true" or "false," only appropriate or inap- 

 propriate. Concepts prove themselves as tools prove tliemselves. 

 James writes (in italics) that: 



. . . our fundamental ways of thinking about things are discoveries 

 of exceedingly remote ancestors, which have been able to preserve 

 themselves throughout the experience of all subsequent time. 



In my instantaneous visual field I register the construct I call "this 

 man." The characteristics of "this man" stand out from the pattern 

 of the concept "man." I then relate my experience of this man today 

 to my experience of that man yesterday and, within limits, predict 

 my experience of this or that man tomorrow. Ability to make such 

 predictions is enormously valuable, and the concepts conveying such 



