I’ve just finished reading David Deutsch’s extraordinary book, The Beginning of Infinity.
It deals with what, on the face of it, may seem a very obscure topic, epistemology, or the theory of knowledge. But it does so in a way that makes it feel immensely relevant to our modern world. It also made me feel much more optimistic, which was a refreshing change from the general gloominess that characterises much contemporary writing.
Deutsch argues that science, and indeed all knowledge, is built primarily on ‘good explanations’.
By this, he means precise explanations that are hard to adjust in any way without ceasing to work.
Thus, a bad explanation might be a detailed creation story based on some god or other incubating and finally hatching open an enormous egg … or, maybe, for those of us brought up in the Judaeo-Christian tradition, a deity miraculously making an entire world in just six days.
This kind of explanation is easy to vary in almost every respect yet still work. For instance, the bird laying the egg might be an ostrich or a hen or a pterodactyl; or the world might be created in 66 or 666 days, and it wouldn’t make any difference. Contrast that with, say, Newton’s laws of thermodynamics which are precise in every respect and cannot be varied in the slightest detail without ceasing to explain the world accurately.
Deutsch agrees with Karl Popper that good scientific theories have to be falsifiable but clearly feels this widely espoused principle has been a bit overplayed.
Most theories shouldn’t even make it to the testing stage, he argues, because they can be thrown out by sheer intellectual challenge simply because they’re not good explanations.
There are echoes here of another famous physicist, Wolfgang Pauli, who once rejected a student’s thesis for being “not even wrong”. Expensive, time-consuming testing simply isn’t needed to expose a lot of bad science.
And it’s at this point that it all starts to get really interesting. Because Deutsch starts to show us how powerful this kind of theoretical challenge can be – and yet, how infrequently it is attempted today.
“Instrumentalist” scientists (of the “shut up and calculate” school of quantum physics) and behaviouralists, in the world of psychology, make the kind of error Deutsch is most worried about. For they regard the explanation phase of a theory to be effectively unknowable and concentrate merely on what a computer programmer would call inputs and outputs, rather than the inner workings of the programme itself.
Deutsch then shows us some of the risks of this “explanation-less science”.
For instance, a gene may be shown by behaviouralists to select for human happiness but, without a good explanation as to how this outcome is achieved, we would not know if we were dealing with a direct effect – an actual happiness switch in our DNA – or an indirect one – such as an enabler of a certain sort of attractiveness, which may, in turn, only produce happiness as a secondary effect where being attractive makes the individual happy.
And this matters. Because if cultural ideas of attractiveness were to change, the indirect mode of happiness generation might eventually fail, whereas a happiness switch would not. So, by not following through with an explanation for his intriguing results, the behaviouralist has failed to identify whether the happiness produced is of the enduring or temporary type. Which suggests that the external, explanation-less approach can produce erroneous, or at least seriously incomplete, interpretations, thus undermining the progress of science.
In the end, Deutsch finds this kind of explanation-less science everywhere.
It’s closely associated with modern relativist ideas, where all opinions are increasingly deemed valid. Deutsch clearly regards this kind of thinking as a cultural aberration and even illustrates his point by arguing compellingly for the reality of deeply unfashionable absolute truths such as right and wrong and objective beauty.
It’s a long long time since I have read a robust defence of the absolute existence of moral truth.
The nearest thing I can think of is C.S. Lewis’s The Abolition of Man which also sets out to (pretty gleefully) demolish modern relativist thinking.
Lewis, like Deutsch, was out of step with many contemporary thinkers and his book comes across as similarly fearless and outspoken.
Of course, Lewis was a Christian and Deutsch an atheist but I feel sure they’d have seen eye to eye on this matter.
One suspects indeed that Deutsch may spend much of his life aghast at the “anything goes” belief systems of those around him though he never lets his exasperation get the better of him, arguing constructively throughout for perennial optimism in the face of inevitable challenges.
As he reminds us repeatedly, problems are soluble and human creativity has proven, over and over, to be able to provide unexpected, imaginative solutions.
We should not despair, therefore, but instead strive to create an environment in which problem-solving can thrive – which, according to Deutsch, is one based on western enlightenment values of creativity and criticism, within the broader context of a dynamic society that welcomes change.
The book is, therefore, ultimately, inspiring. But I finished it also feeling a deep obligation to defend the noble pursuit of meaningful explanatory science and objective truth, coupled with a firm belief that doing so is, fortunately, not yet a forlorn project.
We might sometimes seem to live in a credulous, crazy age that appears to be dominated by politicians, fake news and trolls.
But science and rational thinking still offer us a route to a dazzling future; the Beginning of Infinity.