246 HAS SCIENCE DISCOVERED GOD? 



exist because certain things affect your consciousness 

 and mine in the same way, but we are assuming some- 

 thing we have no right to assume if we label them 

 as either "real" or "ideal." The true label is, I 

 think, "mathematical" if we can agree that this is to 

 connote the whole of pure thought, and not merely 

 the studies of the professional mathematician. Such 

 a label does not imply anything as to what things are 

 in their ultimate essence, but merely something as to 

 how they behave. 



The label we have selected does not, of course, 

 relegate matter into the category of hallucination or 

 dreams. The material universe remains as substan- 

 tial as ever it was; and this statement must, I think, 

 remain true through all changes of scientific or philo- 

 sophical thought. 



For substantiality is a purely mental concept mea- 

 suring the direct effect of objects on our sense of 

 touch. We say that a stone or a motor-car is sub- 

 stantial, while an echo or a rainbow is not. This is 

 the ordinary definition of the word, and it is a mere 

 absurdity, a contradiction in terms, to say that stones 

 and motor-cars can in any way become unsubstantial, 

 or even less substantial, because we now associate 

 them with mathematical formulae and thoughts, or 

 kinks in empty space, rather than with crowds or hard 

 particles. 



Dr. Johnson Is reported to have expressed his 

 opinion on Berkeley's philosophy by dashing his foot 

 against a stone and saying: "No, Sir, I disprove It, 

 thus!" 



This little experiment had, of course, not the slight- 

 est bearing on the philosophical problem it claimed to 



