SCIENCE 9 



although it is hard to say just when, the explanations become sufficiently 

 general, and, since the observations have been repeated by so many 

 observers under so many conditions, widely accepted. When these state- 

 ments are believed and agreed upon by the majority of competent 

 authorities, they are often called theories, principles, or laws. Although 

 these terms differ slightly in connotation, they are commonly used to 

 indicate varying degrees of reliability and acceptability. 



Interestingly enough, this alternation of observation and explanation 

 works in two directions. Some individual phenomenon becomes better 

 understood, so that more is known about this little fragment of the 

 universe. At the same time, the observations turn up new relationships, 

 and we find that we also know more about broader, more general aspects 

 of the universe. 



Limitations of science 



One of the obvious limitations of science is that it can include only 

 what can be observed. Questions of human values, ethics, morals, and 

 religion cannot be touched by science because they cannot be observed 

 objectively. The scientist is free to form his own conclusions on these 

 matters as long as they do not interfere with the objective and imper- 

 sonal observation in his investigations. Some scientists are atheists be- 

 cause they have not observed a god directly. Others call themselves 

 agnostics; that is, they say "I do not know" because scientific methods 

 cannot be used to investigate gods. Still others are deeply religious, 

 believing that the order and consistency of the universe is evidence of 

 a god. There is no inconsistency in any of these positions, and science 

 does not force a man to believe anything that is outside of science. The 

 only quahfication is that his thinking on areas outside of science must 

 not influence his thinking on scientific matters. 



Another less obvious limitation on science depends upon the assump- 

 tions that must be made before starting any scientific activity. We may 

 assume that something is true; we take it for granted, even if it cannot 

 be tested by observation. There are several features of the universe that 

 the scientist so commonly takes for granted that it may even be surpris- 

 ing to see them written down. These assumptions are so deeply en- 

 trenched in everyday thinking that it is difficult to conceive of their 

 tentative nature. And yet none of these assumptions can be tested, and 

 any of them might not be true. 



