“I refute it thus” Or do you? 

Dr Samuel Johnson was once engaged in a debate with his biographer James Boswell about Bishop  George Berkeley’s  theory of Idealism. Boswell takes up the story. 

“After we came out of the church, we stood talking for some time together of Bishop Berkeley’s ingenious sophistry to prove the non-existence of matter, and that every thing in the universe is merely ideal. I observed, that though we are satisfied his doctrine is not true, it is impossible to refute it. I never shall forget the alacrity with which Johnson answered, striking his foot with mighty force against a large stone, till he rebounded from it, “I refute it thus.”” 

Thankfully Dr Burling’s exploration of Idealism did not result in rocks or indeed anything else in Room 5 being kicked. However as was implied by the talk, would we even know there were any objects to kick once we left the room? 

The point is that idealism, the belief that all that exists are senses, impressions, emotions and that the physical world is a mere hypothesis, seems both intuitively wrong but also quite hard to refute.  

Berkely’s dictum that “esse est percipi”, to be is to be perceived, raises the question about what guarantees the continuance of the existence of an object if no human is perceiving it. Are the chairs still in the classroom while everyone is out having lunch? 

Berkely’s answer to this, that God is always perceiving everything was captured in a nice limerick by Ronald Knox: 

There was a young man who said “God  

Must find it exceedingly odd  

To think that the tree  

Should continue to be  

When there’s no one about in the quad.”  




“Dear Sir: Your astonishment’s odd;  

I am always about in the quad.  

And that’s why the tree  

Will continue to be  

Since observed by, Yours faithfully, God.” 


Members of the Year 9 Athenaeum group also thought about dualism and materialism, the rivals to idealism in the debate about reality. The session ended with some speculation about what light Berkeley’s views might shed on the proposition, discussed in David Chalmer’s recent book Reality + that we may all be existing in a computer simulation. 

I wonder what rock Dr Johnson might have had to kick, were he around today, to refute that one. 

Thanks to Dr Burling for expertly unpacking some complex ideas and taking the group onto the next level of philosophical investigation following their work on the nature of reality in Year 8.