EVILS OF IGNORANCE. 25 



so little known, that, if no glaring mischief has fol- 

 lowed any particular practice, within at most twenty- 

 four hours, nine out of ten individuals will be found 

 to have come to the conclusion that it is perfectly 

 harmless, even where it is capable of demonstration 

 that the reverse is the fact. 



It is this apparent but unreal separation of the 

 effect from its cause which has given rise to the 

 variety of opinions entertained in regard to the 

 qualities of the same agents, and which has, per- 

 haps, tended more than any thing else to discourage 

 rational regard to the means of preserving health ; 

 and yet this very variety is a proof at once of the 

 absence of sound views of our own nature, and of 

 the urgent necessity of possessing them. In soci- 

 ety, accordingly, nothing is more common than to 

 hear the most opposite opinions expressed in regard 

 to the evils or advantages of particular kinds of 

 clothing, food, and exercise. One person will affirm 

 with perfect sincerity that flannel is pernicious, be- 

 cause it irritates the skin, and uniformly causes an 

 eruption over the whole body; and that linen or 

 cotton is an excellent article of dress, because it 

 produces no such consequences. Another will tell 

 you with equal truth that flannel is a capital thing, 

 because it is pleasant to the feeling, and affords 

 protection from cold and rheumatism, which linen 

 does not. One will affirm that a long walk or vio- 

 lent muscular exercise is an excellent tonic, because 

 it gives a keen appetite, and a vivacity and alertness 

 which are delightful. But another will declare that 

 a long walk or severe exercise is exceedingly inju- 

 rious and debilitating, because it destroys his appe- 

 tite, and unfits him for exertion of mind or body, 

 "aid always gives him headache. One will, in like 

 jianner, praise vegetables as the best diet, and 

 another animal food as infinitely superior, and so on 

 through the whole range of physical objects which 

 get upon the human frame, and the natural conse- 

 O 



