1901.] on Memory. 607 



The subject of Dynamic Memory is too vast to be more than 

 touched upon. We have seen how the dynamic memory of living 

 matter differs from that of not-living matter. In the one the pro- 

 duction of a set renders more difficult, impedes and obstructs, further 

 change in the same directiou. In the other it facilitates a further 

 change. It needs but little consideration to show that this re- 

 markable property of living matter is the basis of all progress, of all 

 improvement, of all intelligence, eveu of all morality. It is by virtue 

 of this quality of living matter that practice makes perfect, that use 

 becomes a second nature. It is owing to this property that repetition 

 of an experience has so powerful an effect in fixing the memory of 

 the experience. Every repetition of a distortion increases the set 

 which the distortion leaves behind it ; and when the distortion is 

 repeated sufficiently often, the temporary set becomes a true per- 

 manent set. When once a new nervous process has been brought 

 about, when a new fact has been observed, when a new muscular 

 adjustment has been obtained, when a new train of reasoning has 

 been thought out, when a new inhibition has been exercised, a change 

 is produced, a dynamic memory is left in the nervous system, by 

 which similar changes in the future are facilitated. Thereafter, not 

 only is that particular fact more obvious when it is next met with, 

 not only is that particular exercise of skill more easy, not only is 

 that train of reasoning traversed with greater ease and rapidity, not 

 only is that particular control more easily exercised, but beyond all 

 this there is a larger change. Observation is increased in keenness 

 not as to that fact only, but as to all facts of the same class, and in 

 less degree as to all facts whatever. Skill in muscular adjustment, 

 nicety and accuracy and deftness of movement, are increased, not 

 only as to that particular act, but to all kindred acts ; and in less 

 degree as to all acts whatever. Ability to compare and to distinguish 

 likeness and difference is increased, not only with respect to the 

 matter about which we reasoned, but with respect to all kindred 

 matters, and in less degree to all matters whatever. By each act of 

 self-control not only is it easier to exercise self-control with regard 

 to that particular indulgence, but to exercise self-control generally 

 with regard to all indulgences ; and thus on this property that I have 

 called dynamic memory rests, as I have said, all progress and all 

 morality. 



Active Memory is no exclusive possession of the nervous system, 

 nor even of living beings. The nervous system displays active memory 

 not because it is a living tissue, but because it is a mechanism ; and 

 every mechanism, live or dead, animate or inanimate, displays in its 

 working an active memory of the experiences that it went through 

 during its construction. With very many mechanisms, outside as 

 well as inside the nervous system, the structural arrangement can be 

 altered, and thereupon the mode of working is so modified that the 

 output is altered. A lathe may be so set that it produces a screw, or 

 a cone, or a cylinder, or a sphere, or what not ; and the form that its 



