Charles Darwin

Throughout history we have made some fundamental advances in our understanding of the world. Big steps forward after which there was no turning back. Among the most important of these is the one made in the mid-nineteenth century by Charles Darwin.

Darwin’s discovery relates to all the living beings on this Earth: from mice to butterflies; from viruses to elephants. As well as, dear reader, to you and me. The first thing that we understood thanks to Darwin’s work is that all living beings share the same ancestors. We are part of the same genealogy of the one great family to which we all belong. The mother of the mother of the mother of a butterfly in your garden is also the mother of the mother of the mother … of your mother. If you think about it, this discovery is both thrilling and moving. We are all siblings on this planet. And this is a fact, of the same order of certainty as that the Earth is round.

The second of Darwin’s discoveries is the way in which so many diverse forms of life were derived from simple common ancestors. Darwin made two observations. The first, the most important, tells us that within every living species there is great variety. We humans, for instance, are all different from each other. Dogs are even more different from each other than we are. This variety is a universal characteristic of living beings and is always being renewed. The living constantly change and diversify.

The second observation tells us that in nature only a minority of living beings successfully reproduce. The majority die before doing so. For all our civilization, this remains true even for human beings. Most fertilized eggs do not result in births.

If we put together this variety with the fact that only a small part of it reproduces, it immediately follows that living beings continue to change, continually experimenting with countless variants, and that only some of those variants – those most able to survive and reproduce in the surroundings they find themselves in – prosper. The others perish. The living beings that we see around us are those that had the characteristics best suited to allow them to prosper.

The understanding of this mechanism has had a huge cultural significance. In the living world many structures, behaviours and forms appear to be accurately designed for life to thrive. Why is this the case? This was a question that had remained open ever since it was raised by Empedocles and Aristotle. Darwin found the full answer.

The answer is that the question was wrong in the first place. It is the wrong way round. It is like asking why there are doors attached to handles. There can be no reason for attaching a door to a handle. But there is good reason for attaching a handle to a door. Living things do not possess adaptable structures for mysterious reasons: it is only those that have adaptable structures that are living in the first place.

The ramifications of this discovery are far-reaching and contribute significantly to our understanding of the deep nature of things. It shows us that the seeming finality of the biological world is only the result of the richness of combinations of things of which the world is made. There is no such thing as intentionality in nature. It isn’t design that directs the combination of things, but it is the combination of things that gave rise to intentionality. This has led us to take another step back with respect to the naïve animism of antiquity.

It is still possible to believe in the existence of God the creator of the universe even after this discovery, and there are of course many who do. But the discovery of these simple, basic facts about nature has rendered inconsistent various traditional arguments that purportedly showed the necessity of a divine will to make the world go round. Just as understanding where rain comes from or what causes lightning prompted faith in the existence of Zeus to evaporate, so too the understanding of how life evolved and diversified on Earth has vastly multiplied the number of atheists in the world.