104 WHAT IS SCIENCE? 



ARE THEORIES REAL ? 



And here we come to our last question. I have been 

 at pains to distinguish theories from laws, and to insist 

 theories are not laws. But if that contention is 

 true, are not theories deprived of much of their value ? 

 Laws, it may be said, are statements about real things 

 about real substances (such as iron), about real objects 

 such as the earth or the planets or existing living beings) 

 Laws are valuable because they tell us the properties of 

 these real objects. But if theories are not laws, and if the 

 statements they make are about things that cannot ever 

 the subject of laws, do they tell us about anything 

 Are the molecules (by means of which we explain 

 3 properties of gases) or the countless generations of 

 unknown animals and plants (by means of which we 

 explain the connexions between known animals and 

 ;) or the forces on the planets (by means of which 

 we explain their orbit) are these molecules and animals 

 and forces mere products of our fantasy, or are they just 

 s real as the gases and the animals the laws of which 

 they are led to explain ? Are theories merely explana- 

 tory, are they like the fairytales by means of which our 

 ancestors explained to themselves the world about them 

 are they like the tales we often tell to our children with 

 the same object of explanation, or are they truly solid 

 fact about the real things of the world ? 

 That may seem a simple question to which a plain 

 wer, Yes or No, might be given; but in truth it 

 the most profound and abstruse problems of 

 philosophy and really lies without the scope of this book 

 - object is to discover what science is ; we have learnt 

 what laws and theories are, and what part they play in 

 science ; it is not directly part of our purpose to discuss 

 what value all this elaboration has when it is achieved 

 E3ut in a book of this kind it would be wrong to leave the 



