I’ve just finished reading (and writing a review of) a funny little book about quantum mechanics called Quantum Enigma: Physics Encounters Consciousness by Bruce Rosenblum and Fred Kuttner. I won’t repeat the review here for fear of copyright infringement, but I will say that, somewhat to my surprise, I actually liked some of the book although it does go off the rails a bit now and then. Don’t we all, though?
Anyway, one thing did strike me that I didn’t really have time to write about in my piece concerns the philospher George Berkeley (1685-1753). In case you weren’t aware, the town of Berkeley (near San Francisco, in California) is actually named after him.
Berkeley was one of a number of philosophers responsible for the emergence in the 17th and 18th centuries of a movement now known as empiricism. The most striking of Berkeley’s arguments is that matter (or substance) cannot be said to exist in a manner that’s independent of the mind, butHis work has turned out to be nowhere near as durable as some of his contemporaries, notably David Hume, but he’s actually a much more interesting thinker than most people seem to give him credit for. Indeed, many writers – including the authors of the book I mentioned above – dismiss his views as a preposterously naive form of solipsism. Although I’m no empiricist myself, I think this Berkeley-bashing is a bit unfair.
I think Berkeley’s ideas are best understood in relation to the others that were being suggested around the time he was writing, particularly René Descartes whose method was to try to understand what could be known with certainty when all possible scepticism was argued away. In Berkeley’s most important work The Dialogues of Hylas and Philonous (1710) he developed this approach into an argument that only ideas, perceived and created by the mind, could be known with any certainty, doing so through a dialogue between two characters. Hylas represents the view of “normal” scientific common sense (as one imagines would be exemplified by, say, Isaac Newton); Philonous represents Berkeley’s own views.
Time and time again Philonous comes up with ingenious counters to the “obvious” arguments presented by Hylas. Our understanding of what we consider to be actually existing objects to which we attribute certain qualities (such as white clouds or hot water) is essentially a mental affair. Sensations such as taste and pain have no basis in existence outside the mind, but what about trickier concepts like colour? Can it be said that when an object looks red that it must contain in itself the quality of redness? Berkeley says no, because “red” is merely a category and cannot therefore exist in the colour. Of course we now know a lot more about how colour comes about than Berkeley did, but it remains an interesting point.
He suggested quite generally that impressions we get from our senses are not necessarily based on an innate qualities of the objects or substances with which our senses come into contact. For example, our sense of distance is not caused by the actual distance between objects themselves.
I have to re-iterate that I’m not an empiricist and I don’t agree with Berkeley’s position, just that his position is a great deal subtler and more interesting than usually represented. I mis-spent a large part of my youth struggling with impenetrable works of philsophy, but Hylas and Philonous is one I definitely don’t regret reading. Not quite up to the standard of David Hume, mind you, but who is?
So give George Berkeley a break! Karl Popper, on the other hand…
As the 
In the Dark 