Science: The best way of understanding the world?
‘We must constantly check the results of our reasoning process against the facts, and see if they fit. If they don’t fit, we must respect the facts, and conclude that our reasoning was mistaken.’
JBS Haldane, What I Believe
In this section we will explore how science has enabled us to test the apparent evidence we receive through our senses, how it has helped us to develop an understanding of our how our world works based on natural explanations, and why humanists place such value on the scientific endeavour.
The scientific method
We’ll begin by asking: ‘What is science?’
Science is an activity that attempts to enable us to get closer to true beliefs about the world. Its method is to begin with observation of the world and the formation of hypotheses (possible explanations for why things are the way they are). It then requires us to ask what would happen if such a hypothesis were true and make predictions that we can test. It demands that we test those predictions – with experiments – in order to look for evidence that our hypothesis is correct. The more evidence we have, the more confident we can be that our hypothesis is true. We should therefore use further testing to recheck and refine our hypothesis and support our conclusion.
Observation: We see that the plants in our garden only appear to grow when it has rained.
Hypothesis: These plants need water to grow.
Prediction: If those plants don’t get any water, they will not grow.
Test / experiment: We put two plants into separate pots. We water one but not the other. All the other conditions are the same.
Evidence: The plant we watered grew. The one without water did not.
Conclusion: We now have some evidence that our hypothesis is correct. However, to be more confident, we should repeat the test and try to think of other ways to test our hypothesis.
This ability to test our hypotheses is vital to the scientific method. To be a scientific claim is to be testable and capable of being falsified. Claims that cannot be tested and therefore can never be falsified are not scientific.
We cannot, of course, test everything ourselves. We often need to rely on the work of others. Humanists will typically be wary of claims made on the basis of authority alone. However, it is important to acknowledge that we all have to appeal to authority sometimes. No one can be an expert on everything. Humanists believe we should try to limit our trust to those we have good rational reasons to trust. The status and prestige of science rests not on the authority of individual scientists, but on the rational basis behind the methods they use. The claims they make are always open to questioning and investigation. We might not be able to test every claim for ourselves, but that a claim is testable is of great importance.
The best way of understanding the world
‘Science is one of the very few human activities – perhaps the only one – in which errors are systematically criticised and fairly often, in time, corrected. That is why we can say that, in science, we often learn from our mistakes, and why we can speak clearly and sensibly about making progress there.’
Karl Popper, Conjectures and Refutations: The Growth of Scientific Knowledge
For humanists, it is scientific investigation (the testing of claims against evidence) that provides the most reliable method of explaining how the world works.
Science is self-correcting. Scientists can, and do, make mistakes. However, mistakes should be, and are, borne out by further experimentation. Science is fertile in the sense that it generates an ongoing programme of further research with which we can test our existing understanding of the world.
Science is also credible because it does not respond to our wishes about how the world should be. It may not allow us to see the world in terms that we easily understand.
Finally, we can see the reliable practical applications of scientific reasoning in the modern world around us. Every time we switch on a light, are cured by a medicine, or safely end a plane journey, we are provided with further evidence that our trust in the scientific method is rational.
Question: Does science provide us with the best way of answering questions about the world? Does it provide the best way to give ourselves the highest probability of our beliefs being true?