32 The Animal Mind 



test is that the learning by experience must not be too slow, 

 or we can find parallels for it in the inanimate world. An 

 animal may be said to have learned by experience if it be- 

 haves differently to a stimulus because of preceding stimuli. 

 But it is one thing to have behavior altered by a single pre- 

 ceding stimulus, and another to have it altered by two hun- 

 dred repetitions of a stimulus. The wood of a violin reacts 

 differently to the vibrations of the strings after it has "expe- 

 rienced" them for ten years; the molecules of the wood have 

 gradually taken on an altered arrangement. A steel rail re- 

 acts differently to the pounding of wheels after that process 

 has been long continued ; it may snap under the strain. Shall 

 we say that the violin and the rail have learned by individual 

 experience ? If the obvious retort be made that it is only in 

 living creatures that learning by experience should be taken 

 as evidence of mind, let us take an example from living crea- 

 tures. When a blacksmith has been practising his trade for 

 a year, the reactions of his muscles are different from what 

 they were at the outset. But this difference is not merely a 

 matter of more accurate sense-discrimination, a better " plac- 

 ing" of attention and the like ; there have been going on within 

 the structure of his muscles changes which have increased their 

 efficiency, and with which consciousness has had nothing to 

 do. These changes have been extremely slow compared to 

 the learning which does involve consciousness. In one or 

 two lessons the apprentice learned what he was to do; but 

 only very gradually have his muscles acquired the strength to 

 do it as it should be done. Now among the lower animal 

 forms we sometimes meet with learning by experience that is 

 very slow ; that requires a hundred or more repetitions of the 

 stimulus before the new reaction is acquired. In such a case 

 we can find analogical reasons for suspecting that a gradual 

 change in the tissues of the body has taken place, of the sort 



