POPULAE FALLACIES. 85 



POPULAE FALLACIES. 



OF all the means of estimating physical effects, the most obvious, and those 

 upon which mankind place the strongest confidence, are the senses. The eye, 

 the ear, and the touch, are appealed to by the whole world as the unerring wit- 

 nesses of the presence or absence, the qualities and degrees, of light and color, 

 sound and heat. But these witnesses, when submitted to the scrutiny of rea- 

 son, and cross-examined, so to speak, become involved in inexplicable perplex- 

 ity and contradiction, and speedily stand self-convicted of palpable falsehood. 

 Not only are our organs of sensation not the best witnesses to which we can 

 appeal for exact information of the qualities of the objects which surround us, 

 but they are the most fallible guides which can be selected. Not only do they 

 fail in declaring the qualities or degrees of the physical principles to which 

 \ they are by nature severally adapted, but they often actually inform us of the 

 ' presence of a quality which is absent, and of the absence of a quality which 

 is present. 



The organs of sense were never, in fact, designed by nature as instruments 

 of scientific inquiry ; and had they been so constituted, they would probably 

 have been unfit for the ordinary purposes of life. It is well observed by Locke, 

 that an eye adapted to discover the intimate constitution of the atoms which 

 form the hand of a clock, might be, from the very nature of its mechanism, in- ] 

 capable of informing its owner of the hour indicated by the same hand. It 

 may be added, that a pair of telescopic eyes, which would discover the mole- 

 cules and population of a distant planet, would ill requite the spectator for the 

 loss of that ruder power of vision necessary to guide his steps through the city- 

 he inhabits, and to recognise the friends which surround him. The compari- 

 son of instruments adapted for the use of commerce and domestic economy, 

 and those designed for domestic purposes, furnishes a not less appropriate 

 illustration of the same fact. The highly delicate balance used by the philoso- 

 pher in his inquiries respecting the relative weights and proportions of the con- 

 stituent elements of bodies, would, by reason of its very perfection and sensi- 



