Via Darwinism, we can travel back in time through genetic variation and speciation, from the bewildering variety and complexity of life today all the way to the simplest self-replicating single-celled organisms from which all living things are derived.
Nothing in our reverse journey so far has demanded supernatural intervention to function, but obviously, we need some fundamentals, for which we have not yet accounted, for evolution to work with: a universe in the first place, certain chemicals and certain weather conditions.
So while we have explained life (and its meaning) we have not yet accounted for the existence of the universe itself. Is this a convenient place to fit God back into the equation?
It may seem so, and certainly it is a popular spot for sophisticated theologians who wish to have their primordial soup and eat it.
But I think this is to commit a logical error, compounded by the inability to accept that there must be a fundamental given for any speculation to be possible, and that given here is existence.
Without existence there can be no question of anything, so a question of existence is almost by definition one that is impossible to conceive. The trouble is that our brains are sophisticated enough to formulate such questions, which leads naturally to the delusion that we must therefore be able to answer them, or at least conceive of what kind of an answer we are looking for.
The reason why such an error occurs is best illustrated by the following analogy. This is a story that I may have modified considerably in the many years I have been pondering it, but which is borrowed in its essentials from the philosopher Anthony Flew.
Imagine there are two explorers, arduously hacking their way through unexplored jungle, every step requiring the slashing and chopping away of overgrown vegetation, teeming with wildlife.
But then, suddenly, they hack their way into a clearing. After miles of being unable to see more than a foot ahead of them, they suddenly stumble upon a wide-open space.
It is a garden, with ornamental shrubs, a neat lawn, and flowerbeds all around. So obvious does it seem that it cannot possibly have grown in such a fashion of its own accord, both explorers reasonably assume that there must be a gardener responsible for its upkeep, and, starved of human company, sit down to await his arrival.
After several days in which the gardener has failed to appear, one of the explorers decides to look for him. The other remains sitting, content to wait, certain he will come.
A week later, and still no gardener, the rift between the two men becomes deeper.
Now, the first is beginning to entertain the notion that, despite all appearances to the contrary, there may not be a gardener after all. The other is so adamant that this plainly cannot be the case that he tries to account for the garden with recourse to concepts of which he has no empirical experience.
What if the gardener were invisible? What if he were somehow omniscient, omnipresent? A force or entity, able to ‘control’ the garden remotely, in ways undetectable by us?
Satisfied with this explanation, he continues sitting.
But his colleague, now more restless than ever, sets off further to examine the situation and try to make rational sense of it.
After a year of observation and experiment, the first man returns to the garden, triumphant and exhilarated by what he has discovered, and eager to share it with his friend.
In a series of tests and observations, he has discovered the process by which the garden sustains and maintains itself.
He has worked out how it exists, by what mechanism, and he has even worked out the reason why it gives the illusion of deliberate design.
All of this he is able to demonstrate and prove.
His colleague, who by this time has a long, trailing beard and has been sitting so long he is literally unable to move, is curiously resentful of the information, and still refuses to accept its conclusion.
Yes, there may be no ultimate need for the gardener as such, but still he remains certain that he is nonetheless there, somewhere, in some sense and to some degree, if only to oversee the process and check that it all runs smoothly.
At this point, the first man realises that nothing he can ever say will be enough to convince his colleague, because they are viewing the garden in two separate and utterly incompatible ways.
But the more important point to me, though I’m not sure it was the central point of Flew’s version, is that the exact nature of the need to believe evinced by the more credulous explorer has shifted from its original more rational formulation – a need governed by the nature of the empirical evidence – to an emotional and internal one, that looks backwards from the stance of a pre-existing explanation rather than squarely at the fresh evidence.
In other words, he was clinging to the gardener belief purely because he wanted to, perhaps because he felt he had too much invested in it, long after the need to believe had been removed.
The garden as they discovered it demanded explanation, and at that point the gardener hypothesis seemed to fit.
But if a simple materialistic process had seemed equally reasonable at the outset, is there any question as to which they would have favoured?
The little bit of the puzzle that remained unknown to them – how such a process might have come about in the first place – would have needed explanation, but neither would have demanded recourse to so outré a solution as an actual thinking and acting gardener.
This is why there is no need to insert God into the story of existence before the process of Darwinian evolution begins, as a kind of supernatural powder-lighter or overseer, and further, it suggests that the fact we ever felt the need to do so afterwards says something interesting about us rather than about the material universe.