208 THE PRINCIPLES OF SCIENCE 



. . . we have to live today by what truth we can get today, and be 

 ready tomorrow to call it falsehood. 



Not quite tomorrow: to certain ideas we long maintain allegiance 

 even in the face of glaring contradictions. And this is something we 

 must do— for at least two reasons: From our steadfastness in the face 

 of adversity, science first gains the continuity of an orderly evolu- 

 tion. And from our uniform adherence to one body of "established'' 

 doctrine, science first gains the character of a corporate enterprise. 



Substantive Principles 



In what does a mountain-climbing expedition differ from a haphaz- 

 ard scramble of individuals in a wilderness? The expedition can 

 function as such only if its members think and act alike in certain 

 basic matters. All agree to climb that mountain, using these tech- 

 niques, and departing from this base camp. At progressively higher 

 altitudes advanced camps will be established at sites on which, again, 

 all must agree. Suppose the climbing party finally confronted by 

 some obstacle that defies every effort made with the climbing tech- 

 niques they are equipped to practice. They must then cast around 

 for some alternate route, to exploit which one or more of the higher 

 camps may have to be shifted— perhaps to locations earlier urged 

 unsuccessfully by some members of the party. A route that demands 

 relocation of only one, or at most two, of the higher camps will per- 

 haps be worth considering. But the party's resistance to each sug- 

 gested alternate route increases rapidly with the number of such 

 relocations its use demands. If all the advanced camps and the base 

 camp must be moved to the other side of the mountain, the expedi- 

 tion acknowledges its defeat. 



Mounting their assault on some particular experiential mountain, 

 the scientists of a given generation bring to the ascent various con- 

 ceptual and experimental techniques, applied under the direction of 

 the regulative principles all accept as definitive. They take their de- 

 parture from a base camp of substantive principles— laws and theories 

 all accept as essentially indubitable. Prospecting the ascent, concep- 

 tual camps (i.e., less firmly held hypotheses and laws) will be estab- 

 lished at progressively greater altitudes. Major disagreement on the 

 location of these does not break out until the climbing party finds 

 itself in serious difficulties. If attempts to overcome these difficulties 



