Mental effects proportionate to causes. 105 



of children, and in the excitable passions of young 

 men and women. The more immediate cause of this 

 power is the oxidation of assimilated food ; and the 

 source of power in the food is the heat of the Sun 

 stored up in the plants and animals they have eaten. 



The subsequent liberation of power under the in- 

 fluence, often of very slight causes, long after the 

 original cause has ceased to act, has led us to con- 

 clude erroneously that causes are not always propor- 

 tional to effects. Proportionality of effect to cause 

 appears to be universal ; it probably operates in 

 mental as well as in physical actions, our faith in 

 education as a means of intelligence is based upon 

 this ; the more complete the education of a particular 

 individual, the greater usually is his degree of in- 

 telligence. Proportionality of cause to effect is 

 apparently disobeyed not only in physical but also in 

 mental phenomena. Throughout the whole realm of 

 nature, minute circumstances often act as exciting, 

 deflecting, and guiding causes, and contribute to the 

 production of apparently disproportionate effects. 

 Thus a spark will discharge the largest cannon ; a 

 touch determine the most distant electric signal ; a 

 word or look, excite the strongest emotions ; the 

 little change of position of a railway point will direct 

 a train either to distant North or South; the minute 

 change of contact of the telegraph switch, will deter- 

 mine the signal to places wide asunder ; one false 

 idea also at a critical moment will often lead a man 

 or woman to ruin ; and in all these classes of cases, 



