76 Wisconsin Academy of Sciences^ Arts^ and Letters. 



a few years ago. It is adopted as a working hypothesis, and it 

 answers every purpose ; but it is liable to be replaced by other 

 antecedents, as it has itself replaced the theory of deluges. The 

 raising of a body in the air, or its resting on the surface of water 

 may be due, not to a suspension of the law of gravita'tion, or to a 

 change in the specific gravity of elements, but to the unknown at- 

 tractive or repulsive force called magnetism, to other unknown 

 forces, or even, conceivably and within the potentialities of mat- 

 ter, to the influence of a spiritual substance on that body, which 

 latter would not be, any more than the former, a suspension of 

 nature's law, or an interference in nature's sequences, which might 

 go on as usual. The attested fact must be tested as others are, by 

 the rules of testimony ; it must not on a priori grounds, at least, 

 be rejected. Experience informs us of the frequent fact of 

 spirit influencing matter, while the same experience points to an 

 unbroken chain of physical antecedents. What, then, may not a 

 more powerful spirit, if it exists, effect upon that purely potential 

 and passive thing called matter? What unimagined and unim- 

 aginable powers, lying dormant in it, may not be awaked by the 

 energetic touch of vivifying spirit ? 



All this may be called wilful fancy, not based on experience, 

 and not verifiable by repeated experiment. To which I reply, that 

 the asserted event is itself a fact of experience narrated by wit- 

 nesses, while the verification, the repetition of it, supposes that 

 we are able, (1) to explain the event by giving all the antecedents, 

 and so (2) to reproduce or find them, which is precisely what we 

 may be unable to do. In this case we may riot know by observa- 

 tion, but will certainly have no warrant for rejecting the observa- 

 tion of other men. In fact we are obliged, in thousands of cases, 

 to rest contented with the observations of other men, and may 

 have no hesitation in doing so, even if only one man has observed 

 the fact, and we think we can trust him.^ 



^ I know a scientist of many years' experience, who tried to verify certain 

 reported observations on "vortex-rings," and saw hundreds of experiments 

 give a diflerent result. He did not dispute the asserted fact, but, I suppose, 

 assumed, rather, that the antecedents in his experiments were different and 

 produced a diflferent result. 



