“Truth or Beauty” by David Orren

‘”Beauty is truth, truth beauty,” – that is all
Ye know on earth, and all ye need to know.’

(John Keats, “Ode to a Grecian Urn”, last lines)

A random website on this poem says “The exact meaning of those lines is disputed by everyone; no less a critic than TS Eliot considered them a blight upon an otherwise beautiful poem.” But away from the poem these lines do have force, and it’s a force which Orrell argues has misled western thinkers for millennia. It was at a recent talk at the school where I work that the visiting philosopher (Amia Srinivasan) pointed out, to me for the first time, that choosing the most elegant from a range of theories, applying Occam’s Razor, doesn’t actually make much logical sense [unless perhaps it’s inductively good practice? – something outside Orrell’s scope]. Anyway, that should explain the title: questioning the iff relationship between these seductive abstract nouns.

This is a good book. Its basic argument is:

Since the Greeks, and particularly Pythagoras & Plato, scientists have viewed simplicity, elegance, beauty as important criteria for assessing the strength of theories. So explanations which unify (e.g. Newton’s theory of gravity, which linked the motions of apples and planets), or display symmetry (e.g. anti-matter) are privileged.
But this has always been a little irrational (it has to be justified by a priori arguments), and has become a real obstacle to progress in the 20th century, with particle physicists getting bogged down in what likes a fruitless search for a Theory of Everything so simple it can go on nerds’ T shirts. Much of nature (e.g. planetary motion not being circular, evolution’s reliance on genetic corruptions to work at all, the asymmetry of the weak nuclear force) is messier and apparently resistant to “perfect” maths. Other, and more directly damaging, problems come from an over-reductive approach to predicting behaviour of complex systems (weather, genetic, economic): such systems operate in ways which are theoretically impossible to predict from just modelling the behaviour of their “atomic” constituents.
Therefore we need to approach such problems with more right-brain, creative, holistic ideas.

It’s also a really useful introduction to the history of science, especially physics and chemistry, taking the layman fairly gently from the Greeks to string theory.

What I don’t yet understand (as my italics above indicate) is how e.g. a weather system is not predictable from its constituents in theory, not just in practice. I can accept Heisenberg for electrons, but wonder what the justification is for similar claims for complex systems. Is it just quantum uncertainty blown up: the uncertainty with particles necessitates uncertainty in the systems they comprise? If so that’s OK as well, but if not then I’d like to know what does cause the unpredictable Democritan swerves, if it isn’t the behaviour of the systems’ components?

The other issue that I’m not sure fits snugly is Orren’s first arguing against using beauty as a criterion to assess a theory, and then arguing that asymmetry etc. can be beautiful, so it’s OK to select such theories…

Some things which need editing:

p23: Eudoxus was fourth century BC, not third century (he came between Plato and Aristotle, who died in 323BC).
p76: the radius of the nucleus is claimed to be 10^32cm – a missing minus sign I suspect.

Other notes:

p287: Aidan Andrew Dun’s statement about atoms and stories (“The world is made of stories, not atoms”) is attributed here to poet Maria Rukeyser.

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