The power and the limits of science

Science’s success in understanding the natural world motivates some scientists to claim that it is all-powerful and will eventually explain absolutely everything

Science has been spectacularly successful over the past 500 years in its primary job of investigating how the natural world works. Science is wonderful but we must not become so dazzled by its great success that we conclude science is all-powerful, as some do. Apart from the scientific sphere many other spheres also exist that are vitally important for human happiness and flourishing but where science is necessarily silent.

Scientific investigation of the natural world has shown us how the world began about 14 billion years ago in the Big Bang, how the 92 natural elements are forged, how stars and planets form, how our solar system formed five billion years ago, how life began on Earth 3.8 billion years ago, how life evolved from that original simple form, the four physical forces that make everything happen, the large-scale structure of the universe – and much more. In addition to discovering these basic natural mechanisms science has also spun off countless useful applications so today the entire developed world runs on science-based technology.

Science exerts its great power by strictly limiting its investigations to impersonal interrogation of the natural physical world and only asking questions it knows it can answer. The utility of science is knowledge of natural physical mechanisms and the generation of technology. Science can give us atomic energy and cure diseases but cannot tell us whether to make peace or war or how to organise a free and just society. Science can give us power and comfort but not wisdom and happiness.

Science is silent in many areas that are of the greatest important. Science is silent on values, meaning and purpose. A scientific analysis of music or painting would simply catalogue frequencies, amplitudes and chemical composition but not explain beauty. And science is silent on the supernatural. It doesn’t deny the supernatural – it just has nothing to say about it.


A scientific account of something does not necessarily give us the full picture. Mathematical physicist John Polkinghorne illustrates this by considering a kettle of boiling water on a gas ring. Why is the water boiling? Science explains that the water molecules absorb energy from the gas flame, moving about faster and faster until they eventually have enough energy to overcome their mutual attraction for each other and they fly off into the gas phase – steam. The other answer to the question of why the kettle is boiling is I want to make a cup of tea. One answer tells us "how" the water boils and the other "why" it boils. Both answers are true and both are necessary to understand the bigger picture.

Science's success in understanding the natural world motivates some scientists to claim that science is all-powerful and will eventually explain absolutely everything, eg biologist Prof Richard Dawkins and chemist Prof Peter Atkins of Oxford University. And both Dawkins and physicist Stephen Hawking are dismissive of philosophy. In his book The Grand Design (2010) Hawking says "Philosophy is dead. Philosophers have not kept up with modern developments in science". I am unaware of any significant response from the philosophers.

On the other hand, Sir Peter Medawar (1975-1987), Nobel Prize Laureate (1960) in physiology or medicine, wisely draws attention to the limits of science: "That there is indeed a limit upon science is made very likely by the existence of questions that science cannot answer and that no conceivable advance of science would empower it to answer. These are the questions children ask – the "ultimate questions" of Karl Popper. I have in mind such questions as: How did everything begin? What are we all here for? What is the point of living?"

"It is not to science therefore but to metaphysics, imaginative literature or religion that we must turn for answers to questions having to do with first and last things?" (The Limits of Science, Oxford University Press 1987).

Science undoubtedly deserves great respect from all, but not global deference. Philosophy, religion and the humanities in general have their own very important roles in trying to show us how to live good, happy and productive lives. They should get on with their business and stop tipping their caps to science.

William Reville is an emeritus professor of biochemistry at UCC