SCIENCE AND NATURE 27 



believe that there are similar thoughts in the minds 

 of the other persons whose bodies behave similarly to 

 our own. 



A DEFINITION OF SCIENCE 



This discussion was started by the suggestion that we 

 could answer our question, What is Science ? by saying 

 ihat science consists in the study of the external world 

 of nature. For reasons which have been given already, 

 and for others which will appear in due course, I propose 

 to reject that definition of science. In its place I propose 

 to put another, which could have been offered before, 

 but, if it had been offered before the discussion which has 

 just ended; it would hardly have been intelligible. This 

 definition is T Science is the study of those judgments 

 concerning which universal agreement can be obtained^ 



The connexion between this definition and the ideas 

 that we have been considering is obvious. It is the fact 

 that there are things concerning which universal agree- 

 ment can be obtained which gives rise to our belief in 

 an external world, and it is the judgments which are 

 universally agreed upon which are held to give us infor- 

 mation about that world. According to the definition 

 proposed, the things which science studies are very closely 

 allied to those which make up the external world of 

 nature. Indeed, it may seem at first sight, that we are 

 practically reverting to the definition of science as the 

 study of nature and that there is little difference except 

 in words between the definition which is proposed and 

 that which has been rejected. 



But there are two very important differences. In the 

 first place the mere omission of such terms as " nature " 

 and the " external world " is important. For these terms 

 represent inferences from the judgments that we are 

 considering. Nature is not sensations or judgments 



