Archive for empiricism

Hylas and Philonous

Posted in History, The Universe and Stuff with tags , , , , , , , on December 21, 2011 by telescoper

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…

The Necessity of Atheism

Posted in History, Literature, The Universe and Stuff with tags , , , , , , , , on February 15, 2011 by telescoper

In the course of doing a crossword at the weekend, I learnt that the poet Percy Bysse Shelley was sent down from (i.e. kicked out of) Oxford University 200 years ago this month for writing a pamphlet entitled The Necessity of Atheism. He was at University College, in fact. A bit of googling around led me to the full text, which is well worth reading whatever your religious beliefs as it is a fascinating document. I’ll just quote a few excerpts here.

The main body of the tract begins There is No God, but this is followed by

This negation must be understood solely to affect a creative Deity. The hypothesis of a pervading Spirit co-eternal with the universe remains unshaken.

That’s pretty close to my own view, for what that’s worth.

More interestingly, Shelley goes on later in the work to talk about science and how it impacts upon belief. A couple of sections struck me particularly strongly, given my own scientific interests.

In one he tackles arguments for the existence of God based on Reason:

It is urged that man knows that whatever is must either have had a beginning, or have existed from all eternity, he also knows that whatever is not eternal must have had a cause. When this reasoning is applied to the universe, it is necessary to prove that it was created: until that is clearly demonstrated we may reasonably suppose that it has endured from all eternity. We must prove design before we can infer a designer. The only idea which we can form of causation is derivable from the constant conjunction of objects, and the consequent inference of one from the other. In a base where two propositions are diametrically opposite, the mind believes that which is least incomprehensible; — it is easier to suppose that the universe has existed from all eternity than to conceive a being beyond its limits capable of creating it: if the mind sinks beneath the weight of one, is it an alleviation to increase the intolerability of the burthen?

The other argument, which is founded on a Man’s knowledge of his own existence, stands thus. A man knows not only that he now is, but that once he was not; consequently there must have been a cause. But our idea of causation is alone derivable from the constant conjunction of objects and the consequent Inference of one from the other; and, reasoning experimentally, we can only infer from effects caused adequate to those effects. But there certainly is a generative power which is effected by certain instruments: we cannot prove that it is inherent in these instruments” nor is the contrary hypothesis capable of demonstration: we admit that the generative power is incomprehensible; but to suppose that the same effect is produced by an eternal, omniscient, omnipotent being leaves the cause in the same obscurity, but renders it more incomprehensible.

He thus reveals himself as an empiricist, a position he later amplifies with a curiously worded double-negative:

I confess that I am one of those who am unable to refuse my assent to the conclusion of those philosophers who assert that nothing exists but as it is perceived.

This is a philosophy I can’t agree with, but his use of words clearly suggests the young Shelley has been reading David Hume‘s analysis of causation.

Later he turns to the mystery of life and the sense of wonder it inspires.

Life and the world, or whatever we call that which we are and feel, is an astonishing thing. The mist of familiarity obscures from us the wonder of our being. We are struck with admiration at some of its transient modifications, but it is itself the great miracle. What are changes of empires, the wreck of dynasties, with the opinions which support them; what is the birth and the extinction of religious and of political systems, to life? What are the revolutions of the globe which we inhabit, and the operations of the elements of which it is composed, compared with life? What is the universe of stars, and suns, of which this inhabited earth is one, and their motions, and their destiny, compared with life? Life, the great miracle, we admire not because it is so miraculous. It is well that we are thus shielded by the familiarity of what is at once so certain and so unfathomable, from an astonishment which would otherwise absorb and overawe the functions of that which is its object.

Finally, I picked the following paragraph for its mention of astronomy:

If any artist, I do not say had executed, but had merely conceived in his mind the system of the sun, and the stars, and planets, they not existing, and had painted to us in words, or upon canvas, the spectacle now afforded by the nightly cope of heaven, and illustrated it by the wisdom of astronomy, great would be our admiration. Or had he imagined the scenery of this earth, the mountains, the seas, and the rivers; the grass, and the flowers, and the variety of the forms and masses of the leaves of the woods, and the colors which attend the setting and the rising sun, and the hues of the atmosphere, turbid or serene, these things not before existing, truly we should have been astonished, and it would not have been a vain boast to have said of such a man, Non merita nome di creatore, se non Iddio ed il Poeta. But how these things are looked on with little wonder, and to be conscious of them with intense delight is esteemed to be the distinguishing mark of a refined and extraordinary person. The multitude of men care not for them.

I think the multitude care just as little 200 years on.

P.S. The quotation is from the 16th Century Italian poet Torquato Tasso; in translation it reads “None deserve the name of Creator except God and the Poet”.