XX JAMES A. WEISHEIPL. 



tive basis only. (2) It insists that all true knowledge must be 

 ' scientific,' and therefore hypothetical. This means that even 

 the first principles of scientific investigation must be regarded 

 as hypothetical and tentative. (3) It restricts ' scientific knowl- 

 edge ' to investigations modeled on, and employing the scien- 

 tific method of modern physics. This means that the various 

 branches of speculative and practical philosophy, theology, 

 history and so forth are not at all scientific, while biology, 

 psychology, anthropology and sociology deserve the name of 

 ' science ' only insofar as they employ the unique ' scientific 

 method ' of physics. 



Here is not the place to controvert these fundamental points. 

 However, a brief comparison of modem scientific theory with 

 the scientific optimism of Aristotle and the ancients is most 

 revealing. Modern theoreticians apparently have abandoned 

 hope in the power of man's speculative reason; they seem to be 

 content with universal uncertainty and a solitary path to knowl- 

 edge. Whatever may be said of Aristotle's science, he was, at 

 least, much more confident in the powers of human reason and 

 more appreciative of the dignity of scientific knowledge. (1) 

 The tentative status of hypotheses and theories proposed by 

 modem theoreticians falls far short of Aristotle's ideal of scien- 

 tific knowledge. Science, for Aristotle, is the attainment of true 

 and certain causes within reality. Such causes are, of course, 

 discovered only after careful research and analysis. Whatever 

 hypotheses, theories or suspicions one may have during the 

 investigation, they are not to be confused with genuine science. 

 Such hypotheses are indispensable and inevitable, but they are 

 only means to the ultimate goal of scientific explanation. (2) 

 Aristotle's lofty, and perhaps unattainable, ideal of scientific 

 knowledge did not blind him into thinking that all true knowl- 

 edge must be of this type. Defending the dignity of science 

 against the skeptics of the Academy on the one hand, and pro- 

 testing the universality of science on the other, Aristotle saw 

 that not all knowledge can be ' scientific,' that is, demonstrable, 

 for then there would be no beginning. He insisted that the 



