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gardener ? is there any county magistrate, or mayor, or alderman 

 of a borough, to whom it would not be useful to know something of 

 the principles on which what are called sanitary measures are to be 

 conducted ? and is there anyone in any situation in life to whom it 

 would not be a benefit to know something of animal physiology, of 

 the functions of his own body, and of the influence which his bodily 

 condition exercises over those moral and intellectual faculties by which 

 he is distinguished from the rest of the animal creation ? If it did not 

 teach him how to cure disease, it might be useful for him to know 

 how far disease may cure itself, and what are the limits of Nature 

 in this respect ? To man, looking at him as an individual, there is 

 no art so important as that of understanding and managing himself, 

 an art so simply and well expressed by the two significant words 

 rVwflt aeavTov, which were inscribed over the heathen oracle of Delphi. 

 To correct bad habits when once acquired is no very easy task ; a 

 strong sense and a strong will, such as only a limited number of 

 persons possess, are necessary for that purpose. But it would go 

 far towards preventing the acquirement of such habits, if young 

 persons, during the period of their education, were made to understand 

 the ill consequences to which they must inevitably lead, and how, 

 eventually, the body must suffer and the mind be stupefied and 

 degraded, not by the reasonable indulgence, but by the abuse of the 

 animal instincts. 



In the Introduction to his ' Inquiry into the Human Understand- 

 ing,' David Hume, having referred to the remarkable progress which 

 had been lately made in a knowledge of astronomy and other physical 

 sciences, has suggested that " the same method of inquiry, which has 

 been applied with so great advantage in these sciences, might also be 

 applied with advantage to those other sciences which have for their 

 object the mental power and economy." I call your attention to 

 this remark, because it brings me to the consideration of another 

 subject, namely, the influence which the pursuit of the physical 

 sciences, conducted as it has been more or less since the days of 

 Galileo and Kepler, has exercised over other studies, and in the 

 advancement of other kinds of knowledge. It needs no argument to 

 prove, for it must be sufficiently plain to everyone, that other 

 sciences as well as the physical have at the present time a very dif- 

 ferent character from that which they had formerly. It was probably 



