Artillery Row

Why Aristotle was right about causation

The Michael Dummett vs Antony Flew debate: What comes first, the cause or the effect?

“I think Aristotle should be considered for a posthumous Nobel Prize for his discovery of the principle implied in DNA” – Max Delbrück, biophysicist and Nobel Laureate.

It has become tediously fashionable, in the dispiriting context of the Covid-19 crisis, to point out that there is no such thing as “the Science”. This should not count as a revelation, although it is frequently presented as one. As the American mathematician, philosopher, and molecular biologist David Berlinski put it, in pre-Covid times:

“There are now four great physical theories: Newton’s mechanics, of course, Clerk Maxwell’s theory of the electromagnetic field, Einstein’s theories of special and general relativity and quantum mechanics. Each is fundamental. The laws of nature that they express are so compressed and therefore so vatic that they may be written down in no more than half a page.”

Indeed, they are “fundamental”. They are also not consistent with each other. And if there is no such thing as “the Science” when it comes to the “four great physical theories”, it would be eccentric to insist on consensus among those rent-seeking lesser sciences, such as (off the top of my head) epidemiology.

But there is a deeper point: you cannot do physics without (even if unconsciously) doing metaphysics. To claim that there is no such thing as “the Science” is to allude to something more interesting than transient disputes between epidemiologists. The deeper controversies concern what science is; what are the metaphysical assumptions that are in play when scientists do whatever it is they do? What is the nature of the reality it claims to describe?

For science to be viable the natural order must be both intelligible and describable. How is this possible? Because, the scientists tell us, the universe is held together by causal laws. When we then ask, as we must, “what is a causal law and how can it hold anything together?” we move from science to philosophy. And there are few subjects in philosophy more perplexing than the nature of causation, bound up as it is with other perplexities concerning the nature of time, personal identity, and the composition of the human mind (or soul).

Post-Enlightenment science takes it as given that what’s new must be better than what came before it

Philosophers have had some fun with the mystery of how one thing might bring about another. In 1954 the Oxford philosopher Michael Dummett published a paper, “Can an effect precede its cause?” in which he argued that it is in principle possible that something happening now could have been brought about by something which happens in the future (presupposing, thereby, that the future is somehow as “real” as the present). In response, Dummett’s colleague Antony Flew, objected that such a thing is logically impossible, given what we mean by the concepts of “cause” and “effect”.

Flew’s reply to Dummett discloses a conception of causation which was bequeathed to us by Galileo, Newton, and the other High Priests of modern science, and which was given a philosophical ratification by the great (yet frequently misguided) Enlightenment philosopher David Hume. Hume argued that there is no design in nature and that to say that A causes B is to say little more than when you get A, then B will follow. Causation does not involve “necessary connection” but “contiguity and succession”.

There is, on this modern orthodoxy, no more to causation than mechanism. Causal laws describe regularities in nature, and this is where explanation comes to an end. The natural world contains no intrinsic purpose, meaning or value. To use a current cliché: it is what it is. Any appearance of value is a chimera, a sort of projection by our minds onto the world, rather than an objective feature of it. And those same minds are ultimately in themselves no more than brains, susceptible to the very same mechanistic “explanations”.

Aristotle’s vision of the world was of one rinsed in purpose and value

This is a depressingly reductive worldview. It is also a comparatively recent one. Like the teenager who assumes he knows better than his parents, post-Enlightenment science takes it as given that what’s new must be better than what came before it, a principle which is neither scientifically testable nor self-evidently true. There is an alternative view of causation, one which is metaphysically richer than the Humean analysis, and which validates our intuition that there is more to the natural order than mere mechanism. This alternative can be traced back to Aristotle, was modified by Aquinas, and is in no way vitiated by its antiquity.

For Aristotle, the mechanistic (or as he put it the “efficient”) causation described by Hume presupposes and is dependent on what he calls “final” causality. You strike a match, and it sets light. The efficient cause of the lit match is that it was struck, but there is more to it than that. The match itself has an essential property of being disposed to catch fire when lit. It is this intrinsic potentiality, its “final”, directed causality, that makes the efficient causation possible in the first place.

This is not “angels on pinheads stuff”. To rehabilitate our conception of causation in a way that takes seriously the possibility of final causality is to acknowledge the intuition that there is an “immanent teleology” to the natural order. The mechanistic worldview of Hume is in stark contrast to the Aristotelian vision of a world rinsed in purpose and value.

And it is the Aristotelian metaphysics which has been gaining in plausibility as science develops, particularly (and pertinently, given the current crisis) in the areas of molecular biology and in our understanding of the galactic complexity of the living cell. It is exceedingly difficult to describe the intricacies of DNA replication without using the language of purpose, a linguistic resource which is not available to defenders of the mechanistic worldview.

Developments in the harder sciences: mathematical physics, cosmology and molecular biology seem to inculcate a reconnection with an Aristotelian conception of causation. Science may progress in utilitarian terms – we can do more with it now than 100 years ago – but it does not follow that its underlying assumptions evolve in the same way. The most prominent philosopher of science at work today, the atheist Thomas Nagel, argued in his book Mind and Cosmos, that it is pretty hard to develop some science-based, plausible worldview which has been voided of teleological explanation. For Nagel, this teleology is a mysterious brute fact, as he is temperamentally and intellectually resistant to draw the obvious theistic conclusions.

As science “progresses”, the antiquated assumptions of 2,500 years ago become increasingly vindicated. We shouldn’t be surprised. Truth is truth and, sub specie aeternitatis, we are talking about the mere blink of an eye. And this is significant because, if the Aristotelian vision is correct, then science is an examination of threads of purpose which have been placed from elsewhere. If Hume is right then, well, “it is what it is”. Is that ever satisfactory as an explanation?

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