CHOICE AND CHANCE. 37 
el ULOS Olea, 
CHOICE AND CHANCE. 
BY FRANCIS E. NIPHER, 
PROFESSOR OF PHYSICS IN WASHINGTON UNIVERSITY.* 
In a lecture delivered in this city during last winter, and entitled ‘‘ Thoughts 
on our Conceptions of Physical Law,” some points were lightly touched which it 
seems desirable to develop more at length. For the sake of brevity, some of the 
statements which will be made have assumed a slightly dogmatic form. They 
are not so intended. Be kind enough to regard them as thoughts of the truth of 
which we are in some cases all more or less uncertain, which are submitted to the 
judgment of sober minds. It does not make a statement true if the whole world 
affirms it; the world has often blundered. This consideration suggests the frame 
of mind in which we should approach difficult subjects where men are likely to 
differ in opinion. He who comes to debate—to defend previously formed ideas 
—is at a disadvantage. It is difficult for such persons to place a proper value on 
the thoughts of others. In this manner the chances for error are increased. The 
method of the scientific man should be different. If he investigates phenomena, 
he seeks to use methods of experiment which eliminate from his results the per- 
sonal bias of his own mind. He must learn to have no preference for one fact 
over another. He must learn to have no anxiety about the result. He must learn 
to be stringently honest with himself—a most difficult thing. If he works induc- 
tively, he should try to find out what @// of the facts teach. If he has occasion 
to frame an hypothesis, and wishes to work deductively, then his work is, not zo 
demonstrate, but to zest the truth of his hypothesis. In the debating school, young 
men are taught to defend assumed positions. In the Academy of Science it 
should be our only object to search for truth. When we differ it is better to 
think, rather than to dispute. 
In the transaction of business we are constantly estimating chances, or prob- 
abilities. All our predictions for the future, even when based on the experience 
of centuries, are simply more or less probable—in no case certain. We cannot 
be absolutely certain that the sun will rise at its accustomed time to-morrow. It 
is wholly in accord with human experience and with the theory of probability, 
that very unexpected things will occasionally happen. 
If we were to learn the contents of an urn, containing a million balls, by 
drawing the balls one by one, replacing them each time, we might, in course of 
time, gain a general idea of the contents; thus if 100,000 draws gave each a 
* Delivered before the Kansas City Academy of Science, Feb. 18th, 1880. 
