ESSAYS 



VERIFIABLE KNOWLEDGE (George Shann) 



The theory of knowledge has often been treated as a branch of metaphysics ; 

 the following is an attempt to deal with the subject of the nature and func- 

 tion of knowledge from a scientific point of view. 



It will be convenient to start with certain hypotheses and to leave the 

 question of their validity for later consideration. First, then, it is supposed 

 that the changes in consciousness which go to form the knowledge we are 

 considering are, at least in part, direct reactions of a nervous organism to 

 stimulus. Secondly, that reactions to simultaneous stimuli tend to become 

 associated together in consciousness and that, since each reaction occupies 

 an appreciable interval of time, a somewhat similar association may take 

 place between reactions whose durations overlap. Also, that in conse- 

 quence of this, the experiences of which we are conscious come to be felt 

 as a continuum, even though the stimuli should be discontinuous like pic- 

 tures in a cinematograph. Thirdly, that when two reactions have been 

 thus associated a more or less permanent connection remains in memory, 

 so that if one of the stimuli be subsequently repeated the reaction to it may 

 include traces of that reaction to the other stimulus by which it was 

 accompanied on the previous occasion. In virtue of such connections long 

 series of nervous reactions can be linked together without any other nexus 

 than their having frequently occurred in close succession ; thus it is com- 

 mon for Oriental students to learn and to repeat the sounds of whole chapters 

 of their sacred books, the language of which is unknown and conveys to 

 their minds no meaning whatever. \ 



Knowledge depends upon mental arrangements in series, but the nervous 

 reactions of a highly organised animal are innumerable ; no single series 

 can include them all ; there must be some selection. Even the rudimentary 

 kind of knowledge above mentioned requires that the sequence of auditory 

 reactions should be segregated from the various other reactions by which 

 they must have been accompanied. The nature of the selection is usually 

 determined by certain indirect, or secondary, reactions, which are called 

 suppositions, or hypotheses, because they are put under the sequences of 

 direct reactions to bind them into the fabric of knowledge. Thus if certain 

 visual sensations at one moment be followed by certain others shortly 

 afterwards, the sequence may be associated in series by the hypothesis that 

 the stimuli to which the sensations respond are due to something outside 

 consciousness, called matter, and that the two stimuli come from the same 

 material body, seen successively in two different places because it has moved 

 from one to the other. 



It is not, I think, too fanciful to compare these direct and indirect reac- 

 tions with the warp and woof of a textile fabric ; the warp being laid down 

 as a foundation, while the woof, determining which threads of the warp 

 shall appear in a given place and which shall be hidden, not only binds the 

 whole together, but also produces the pattern. 



A theory of the construction of mental series having been propounded, 



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