EMPIRICAL TOOLS AND EMPIRICISM 153 



interlocked phenomena of nature, and seek escape to experimental 

 systems that better approximate the simple "ideals" figured in our 

 conceptual abstractions. From raw phenomena— complicated by 

 multiple accessory effects and subject to the action of a host of vari- 

 ables difficult to identify, much less to evaluate— we seek escape to 

 experimental systems in which, by isolation and control, we suppress 

 the accessory effects, diminish the number of active variables, and 

 make the remaining variables amenable to our adjustment. How 

 much more easily we grasp the function in nature of a biochemical 

 intermediate when, in the laboratory, we can study it in a wholly un- 

 natural state of high purity! How much easier it becomes to establish 

 the conjectural effect of a hypothetical variable when we can make 

 it the onlij variable! And, more generally still, given reproducible 

 laboratory data, we must always find it simpler "to see the thing" 

 because, to some degree, at last we can see the simple thing. 



By such experimentation on "parts" we acquire the understanding 

 with which, often, we can mount a successful attack on the still formi- 

 dable problem of giving a complete conceptual reconstruction of the 

 integral phenomenon— which is so completely refractory when sub- 

 ject only to observation as such. Consider Pasteur. He finds the sour- 

 ing of milk far too complex and irreproducible to study directly. He 

 elects to study this fermentation in a medium constituted of chalk, 

 water, sugar, and yeast extract, to which he adds no more than a pin- 

 point's worth of material derived from milk. He proposes to grasp 

 the essence of what happens in milk by studies made on the more 

 controllable medium that, in effect, contains no milk. But then, hav- 

 ing completed his studies on "sugared yeast water," Pasteur finds it 

 possible to return to the souring of milk with an understanding made 

 manifest by his ability to predict its vagaries and, most important of 

 all, to conceive the possibility of something wholly new: the process 

 we know as pasteurization. Precisely in the overivhelming success of 

 such a return— from an ever-so-remote realm of superficially absurd 

 conceptual and experimental abstractions— the scientist's capacity 

 ever to maintain contact with the natural world is most convincingly 

 demonstrable. 



Goethe criticizes Newton for having gone into a darkened room to 

 study light. This criticism was made when the empirical tools of sci- 

 ence were still relatively simple. Today, when scientists devote so 

 much of their attention to subtle effects unobservable without the aid 



