4 THE SEVEN FOLLIES OF SCIENCE 



plane triangle in which the three angles would measure 

 more than two right angles, would show by this very claim 

 that he was entirely ignorant of the first principles of 

 geometry. The same would be true of the man who 

 would claim that he could give, in exact figures, the diag- 

 onal of a square of which the side is exactly one foot or 

 one yard, and it is also true of the man who claims that 

 he can give the exact area of a circle of which either the 

 circumference or the diameter is known with precision. 

 That they cannot both be known exactly is very well 

 understood by all who have studied the subject, but that 

 the area, the circumference, and the diameter of a circle 

 may all be known with an exactitude which is far in 

 excess of anything of which the human mind can form 

 the least conception, is quite true, as we shall show when 

 we come to consider the subject in its proper place. 



These problems are not only interesting historically 

 but they are valuable as illustrating the vagaries of the 

 human mind and the difficulties with which the early in- 

 vestigators had to contend. They also show us the bar- 

 riers over which we cannot pass, and they enforce the 

 immutable character of the natural laws which govern 

 the world around us. We hear much of the progress of 

 science and of the changes which this progress has 

 brought about, but these changes never affect the funda- 

 mental facts and principles upon which all true science is 

 based. Theories and explanations and even practical 

 applications change or pass away, so that we know them 

 no more, but nature remains the same throughout the 

 ages. No new theory of electricity can ever take away 

 from the voltaic battery its power, or change it in any 

 respect, and no new discovery in regard to the constitution 



