158 EMPIRICAL TOOLS AND EMPIRICISM 



Polanyi's striking juxtaposition of the achievements of two 'Tieroes" 

 of scientific history. 



. . . Vesalius is praised as a hero of scientific scepticism for boldly re- 

 jecting the traditional doctrine that the dividing wall of the heart was 

 pierced by invisible passages; but Harvey is acclaimed for the very 

 opposite reason, namely for boldly assuming the presence of in- 

 visible passages connecting the arteries with the veins. 



We praise Vesalius for so cleaving to the "testimony of the senses" 

 that he could reject what all since Galen had accepted. But we also 

 praise Harvey (though we condemn Galen) for going beyond the 

 sensory evidence— to a degree denying its authority— in order thereby 

 to "make sense" of the observables. And both Vesalius and Harvey 

 (but not Galen) will ordinarily be claimed for the sacred flock of 

 practitioners of Method. 



Certainly scientists are responsive to the authority of facts; pre- 

 sumably in this they are much more responsive than the generality of 

 men. But the absolute authority of facts has been denied— and, we 

 say, most nobly denied— by some who could not otherwise have made 

 the scientific advances for which we honor them. Science is irreduc- 

 ible to a "safe" fealty to "indubitable facts." Often, to advance, men 

 must venture boldly, sustained by nothing stronger than a human 

 faith in human ideas that might well prove wrong— preconceived 

 ideas defended warmly even in the teeth of contrary evidence. We do 

 right to honor Mendeleev who— to sustain his periodic classification- 

 had to reverse the positions of tellurium and iodine on the optimistic 

 ( and quite erroneous ) assumption that major errors had been made in 

 determining their atomic weights. 



Facts are not enough; empiricism is not enough. Consider the evi- 

 dence gained by asking: Who advances science? Among the early 

 members of the Royal Society were many who sought to conduct sci- 

 ence as an exercise in Baconian empiricism. But the most notable ad- 

 vances in the science of that age were not the work of these faithful 

 cataloguers of facts: de Maistre indeed suggests that generally those 

 who have taken Bacon most seriously have had the poorest success. 

 Might one then argue that what fails here is not Method, but only 

 men holding an imperfect conception of Method? One will then pre- 

 dict that among moderns the older scientists, with a lifetime's ex- 

 perience of Method, should far excel dieir younger colleagues in the 



