Under the Microscope/Prof William Reville: Most natural scientists believe that the methods of science alone will eventually explain fully what it means to be human. Personally, I doubt this.
Many non-scientists feel that, in making this claim, science displays great arrogance. In fact, this attitude may be conditioned more by lack of confidence in human nature than by arrogance, as I will explain later.
The methods and approach of the natural sciences were originally developed largely to investigate the inert world of nature. These methods may be inadequate and inappropriate to explain uniquely human attributes such as consciousness. The scientific approach in this area has been colourfully compared to that of a drunk walking down a road at night time. The road is lit by lamp posts spaced at 100-metre intervals, each throwing out a limited pool of light that fails to penetrate much of the space between the posts. The drunk drops his car keys in the gutter mid-way between two lamp posts. He then walks 50 metres to the next lamp post to search for the keys, because that's where the light is!
Advances in science since the 1600s have progressively erased human preconceptions about its place in the world. Prior to the Copernican-Galilean revolution, humanity was universally thought to reside at the pinnacle of the universe. It was felt, understandably, that our earth, the home of such an exalted creature, would be located at the centre of the universe. Science has since shown us that we live on a small planet revolving around a very ordinary star in a galaxy containing billions of other stars, in a universe containing billions of galaxies, and that we do not sit at the centre of our own galaxy, much less at the centre of our universe.
Prior to the introduction of the theory of evolution through natural selection in 1858, it was universally accepted that humans were entirely different to other animals. However, science has shown us that humans are descended from ape-like animal ancestors. Nevertheless, until the early part of the 20th century, it was generally accepted that humans had unique properties that transcend the characteristics of other animals - properties such as rationality, consciousness and free will. Humans were clearly seen to clearly stand apart from other animals.
However, the 20th century brought unprecedented horrors - horrors created by humans. Human intransigence and fanaticism produced the carnage of the two world wars. Human attempts to improve society produced the horrors of the Holocaust and the gulags. Human technology and human politics produced nuclear weapons capable of destroying the earth. Human exploitation of the natural riches of the earth damaged the environment and drove some biological species to extinction.
This 20th-century catalogue of human-induced misery profoundly depressed the psyche of the intelligentsia of the developed western world. In a nutshell, the West lost confidence in humanity. All ideologies are now treated with suspicion, as are European cultural traditions. A large variety of conflicting beliefs and practices are treated with equal respect, provided the exercise of any one of them does not interfere with the exercise of any other.
Science has also been susceptible to this intellectual fashion in thinking. It has minimised its expectations of human nature and concentrates on humans as animals rather than transcendent animals. The simple truth of the matter is that, although humans are part of the animal world, humans also transcend the animal world because of consciousness, rationality and free will. Humans, unlike non-human animals, are not merely actors in the drama of life, but also play a part in composing and directing that drama.
If science insists that human behaviour can be fully explained by the laws of physics and chemistry and the automatic playback of evolutionary installed biological programmes, and plays down the transcendent characteristics of human nature, then science is in danger of copying the drunk who lost his car keys on the darkened road. Such a scientific approach may well go a long way towards explaining the nature of non-human animals, but it falls far short of what is required to understand human nature.
Whatever it is that makes us uniquely human sits in the human mind, which depends on the human brain. Science can describe the structure of the human brain and analyse its function in terms of the laws of physics and chemistry, but I doubt that this will ever fully explain the human mind. It is one thing to say that the human brain and mind depend on the laws of physics and chemistry; it is entirely another to say that the laws of physics and chemistry entail the human brain and mind. A building will only stand if it rests on an adequate foundation. But the most thorough examination of the foundation of a building will neither predict nor explain the architecture and function of that building.
Science should, of course, continue to study the biochemistry, physiology and microstructure of the brain. While I don't think this in itself will ever fully explain the human mind, I think it is equally true that this knowledge will provide an essential foundation for this eventual full understanding. But, I believe that a substantial part of the full understanding of consciousness will be metaphysical in nature.
William Reville is associate professor of biochemistry and director of microscopy at University College Cork