This appeal to evidence, however, is not as strong as we normally think it is. For in examining these debates, the key is clearly how ‘evidence’ is interpreted. Evidence in and of itself – that is, the different observations and measurements collected by scientists in their daily work – is not unambiguous.
A good historical demonstration of this ambiguity is the parallel investigations carried out by Priestley and Lavoisier at the end of the nineteenth century. The experiments that each scientist made were broadly the same, as were the factual results. However, Priestley took the evidence as confirming the existence of phlogiston, whereas for Lavoisier the evidence was taken as confirming the existence of oxygen. Each scientist operated within a different overall pattern of understanding, and that governed their interpretation of the relevant data.
This is not a particularly controversial point. Indeed, it is now commonly accepted – the current expression is that ‘there are no uninterpreted facts’. There is a tension between experimental data and the governing interpretation used to understand that data, and the two are engaged in a continual iterative dance of cross-fertilisation, interpretation and translation. It is not simply that a particular governing understanding is the best explanation of the available evidence, nor that singular facts govern the nature of the understanding employed. Instead there is a dialectical process of interpretation, where one side continuously informs and is informed by the other.
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The debate between the different schools in evolutionary biology – those associated with Dawkins, and those associated with Stephen Jay Gould – has become notorious for its ill-temper, often played out on the pages of the New York Review of Books. Yet clearly there is much on which the two different schools of thought agree on: the acceptance of a Darwinian account of evolution, including natural selection, variation and differential reproductive success. Unlike the creation scientists both sides accept that the earth has existed for billions of years, that there never has been nor ever will be any ‘special creation’ of species outside of their development in evolutionary terms, and also that the progress of science genuinely improves our knowledge of the world.
Yet just as clearly each side thinks that something very important is at stake – that the other side has got something seriously wrong. Which serves as a clue that perhaps the main difference between them lies in different answers to the serious questions – that, in fact, the principal disagreements between them lie in different overarching frameworks of understanding. From the atheistic Dawkins, via the humanistic Gould, through to the conservative Christian creation scientists – clearly there is a wide variety of opinion on the serious questions.
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Consider the various transitions in the history of physics – from the Ptolemaic, geocentric view of the world, to the Newtonian system, through to the modern understanding derived from Einstein and quantum physics. In each case the dominant understanding had certain other beliefs ‘built in’.
Ptolemy assumed that the earth was the centre of the cosmos; that things had a particular nature (earth, air, fire, water) and that those things tended to their ‘natural’ place – with the earth at the centre, which explained why things fell down to earth – and heaven beyond the stars. Humans were given the central role in a cosmic drama. Hell was beneath our feet, and very hot; heaven was above the sky, and was ethereal.
In contrast to this, Newton described the world as a mechanism, rather like a clock; it was a machine that had been set in motion by a divine creator, but that since that first impetus the clock had proceeded according to certain discernible laws – of motion, gravity and the like. That machine operated within a framework of absolute space and time. In the Newtonian system, we are essentially machines, composed of various parts interweaving mechanically in a closed system that would inevitably run down.
After Einstein, this ‘clockwork’ model has been rejected, along with the idea of ‘absolute’ space and time. Time speeds up or slows down according to where you are in relation to what you want to measure. The only constant is the speed of light. In this contemporary understanding, our view of physical reality cannot be divorced from how we look at it – if we look for one thing, then we cannot find another. We are still working through the implications of that development.
A natural question might be: will there be another Einstein to come along in a few hundred years to provide another understanding, a different constant?
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What I would like to emphasize isn’t simply that science has a revolutionary history, although that is something that needs always to be borne in mind, but that what drives the debate – what underlies the differences between the different accounts – is something deeper than questions of evidence or rationality. These questions of evidence and rationality are conventional scientific questions – what the ancient Greeks called ‘physics’. What lies behind them is something called ‘metaphysics’ – from the word ‘meta-‘, meaning ‘after’ or ‘above’. Metaphysics, then, is how we can start to describe the domain of our serious questions. In each case there have been claims made that ‘this is how things are’ – with consequent metaphysical implications also claimed.
So when Richard Dawkins writes that ‘…our own existence once presented the greatest of all mysteries, but… it is a mystery no longer because it is solved’ he is not simply describing a scientific conclusion, he is also advocating a particular metaphysical stance, a particular view of what science is and what it can provide. That metaphysical stance can be described and underpins the difference between the two schools of thought in evolutionary biology. For Dawkins is a staunch believer in the ability of science to provide for human progress, whereas Gould sees the relationship between science and society as a much more complex system.
Interestingly, that brief glance at the Newtonian model throws up an interesting parallel, for Dawkins also sees the universe as essentially a clockwork mechanism. Ironically he has a much deeper agreement with Paley – the person who originally conceived of the ‘watchmaker’ argument for the existence of God – than he seems ready to contemplate, for whilst Dawkins tweaks the model to provide his ‘blind’ watchmaker, the idea that the universe is best understood as a watch (ie as a Newtonian system; DNA succession tumbling down the generations like the mechanisms driven by a watchspring) is common to both. Dawkins’ account of evolution is thoroughly Newtonian in its metaphysical assumptions.
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Yet the question remains: is Dawkins correct? If we cannot reach a final conclusion based on logic or purely evidential considerations, can we yet determine an answer to that question, either positively or negatively?
In other words, just how it is that we choose between different understandings?