The Philospher’s Beard
Razor blades come in packs containing ingenious attachments which carry three cutting edges each. These are supposed to trim each separate whisker three times, close, closer and closest to the skin.
Plato had a luxuriant and probably tangled beard. If he had wanted to shave he might have had a bronze blade.
In the thirteenth century, if a philosopher wanted to shave he would have used a steel knife. It would have been a slow, painful and dangerous process.
A great thinker like William of Ockham would surely never have wasted time on such a thing. He was excommunicated by the church.
It is surprising that Ockham’s razor has become famous in modern philosophy, since he probably never had one. What this phrase has come to mean now is: entities are not to be multiplied beyond necessity. A simpler statement came from the clean shaven Bertrand Russell: It is vain to do with more what can be done with fewer. A way of simplifying even further is to say that when we try to understand something, the simplest possible adequate explanation is the one to use. This, we hope, will avoid painful tangles.
For example, it is possible to explain the apparent motions of the, sun, moon, planets and stars by adopting the bearded Aristotle’s theory that the earth is surrounded by a whole series of invisible, interactive spheres and counter-spheres which carry the heavenly objects round and round. If some new observation indicates that another rotating and tuneful sphere is needed, then let us invent one or more, as required. This can go on indefinitely and has the advantage that the earth remains the centre of all.
This is reassuring if, in our human vanity, we want to believe it. The trouble is that it becomes too complex. More and more spheres, more entities, have to be invented until they become multiplied beyond comprehension. Since the object of explanation is to understand, this becomes self-defeating. Ockham comes in with his sharp intelligence.
Copernicus, bearded, in the 15th Century adopted a heliocentric explanation. This was simpler, but heretical. He narrowly escaped excommunication. He had to offer his theory as an alternative, mathematical, abstract idea, not a true explanation.
Giordano Bruno was not so lucky, or not so wise. He was burned at the stake in the year 1600, for proposing, among his other sins, that not even the sun was central. In an infinite universe, he said, there must be millions of inhabited planets. The identical claim can be found in a very recent issue of the very respectable magazine, Scientific American. It has taken four hundred years to catch up with Bruno. I don’t know if he shaved or not but he was well ahead of his time so I guess he was clean shaven.
In modern times we are confronted with explanations of the physical universe that seem to be approaching, even exceeding, Aristotelian complexity. We used to imagine an atom to be a basic, very tiny, lump of hard stuff, incapable of division. The neat and tidy table of the atomic weights rendered the world comparatively easy to understand even though there were some awkward gaps here and there, and some of these little lumps were found to give off dangerous radiation, which contradicted the supposition of solid and rigid unity.
We now suppose that there exist a great plurality of sub atomic entities that exhibit the character sometimes of particles and sometimes of waves, sometimes both at once.
We are no longer confident of our observations; Werner Heisenberg proved we cannot simultaneously measure both the speed and location of particles, or as some call them, wavicles. They can apparently be in two places at once, may even travel backwards in time. Did he shave or didn’t he? I am not sure. Maybe both.
There is a multiplicity of names. Vast sums of money and thousands of hours of work are put into huge machines intended to establish the existence of the Higgs Boson, a theoretical entity widely believed in, but which may, after all, be missing.
A philosopher confronting these issues soon meets what is called the Duhem-Quine thesis. Duhem was a French shaver who died in 1916. Quine, who I mentioned in a previous talk, died, beardless, in the year 2000. Their argument, in crude summary, is that no theory can ever be finally disproved. A latter day Aristotelian may still go on inventing more and more heavenly spheres in order to accommodate modern observations in an extremely complex, but always earth-centred theory of the universe. Copernicus’s heliocentric theory is not proved wrong even though modern measurements show that the orbit of the earth is not, as he supposed, perfectly circular. He could amend the definition of circularity.
So with Newtonian theories of gravity. We still accept Newtonian mechanics, with the qualification that they are confined within certain limits of size and speed. In the appropriate context Newton’s laws make very good pragmatic truth.
So with modern quantum and relativity theories. We can accept both, despite their incompatibility, providing we are prepared always to work with each inside its restricted regions of relevance. So long as we are prepared to modify and modify again the viewpoint we take, we can hold anything to be true. We shift, and shift again, the cultural ground on which we may have supposed ourselves to stand securely.
We can, and do, still use the geocentric theory. Anyone can see that the sun rises, moves around and across the sky and sets. That is true.
Light rays are affected by gravity. We can measure their deflection as light from a distant star passes the sun. The theory of relativity is true.
Relativity conflicts with Quantum theory but this also is true if we change to the necessary frames of reference.
Quine called on us to abandon Plato’s beard, a tangled doctrine, which with its luxuriant population of shadowy and unspeakable entities, has proved tough, dulling the edge of Ockham’s razor.
The physicist Robert Oppenheimer once said, the Universe is not merely stranger than we think, it is stranger than we can think. We must now take seriously the notion that there infinitely many alternative universes.
What we cannot do any more is maintain that there is something called eternal truth existing somehow in never never land. This was the hirsute Plato’s main thesis. We dismiss it now.
Any understanding we have is limited, human and cannot be otherwise. For us there are many truths, useful for their different purposes, to be picked up and abandoned according to need.
Perhaps a triple bladed modern razor going over everything thrice, will help, but the final beardless, naked truth will never be revealed.