How do we acquire knowledge in the natural sciences?
1. The scientific ‘method’
400 years ago, Galileo set up an experiment to test the hypothesis that objects accelerate when they fall. Experimentation was commonly employed by the Arabs, but their methods were looked down on by the Europeans, who followed the Church’s dictum that conclusions could only be reached by discussions and logic, following Aristotle.
Galileo’s reliance on empirical knowledge led Europe into the Enlightenment, and established the scientific method, which is still regarded as the only satisfactory approach when it comes to the acquisition of knowledge about the natural world.
The stages of the scientific method
Watch this clip, and write a short description of each of the following stages of the scientific method.
- The problem
- Peer review
- Replication or falsification
- Corrections and modifications
Science should, therefore, provide an explanation based on impartial research backed by rigorous checks and balances, and not belief. False scientific evidence should never get past stage 4, let alone become a theory.
2. Serendipity in science
Serendipity is a very peculiar English word, with a very specific meaning. It is a very useful when applied to discoveries in science that have been made ‘by chance’, although as Louis Pasteur said, ‘Chance favours the prepared mind.’ The best way to understand the role of chance is to focus on specific cases, and below there is a list of examples from which you can find these. Do they support Pasteur’s assertion?
- The pacemaker
- Safety glass
3. The role of induction and falsification
We have seen that the scientific method involves formulating a hypothesis. There are many ways in which a scientist may arrive at their hypothesis (including serendipity), but probably the most common one is observationalist-inductionism – that is, observing that a phenomenon has always occurred that way in the past, and inducing that it will always happen that way in the future. Proving this hypothesis to be true will be the aim of their experimentation during the testing stage.
To put this in context, let’s say that I am the first scientist to notice that water always boils at the same temperature, 100˚C. Using induction, I suggest the hypothesis that water always boils at 100˚C. I then set out to test this hypothesis, and boil water over a period of years, and always arriving at the same conclusion. I submit my findings to a respected journal, my peers check my findings, and my hypothesis is published. No one refutes my idea, and my hypothesis duly becomes a theory. Over time, the theory then becomes a law.
But there is a problem with this way of viewing science. We cannot prove anything with 100% certainty in the natural world, so the purpose of science is not to show that things are true, rather that things are false. If a hypothesis stands up to testing over a long period of time, it is given the term theory. This means that we are not so much interested in theories that are true as we are theories that are not false.
This idea provides us with a convenient definition of a scientific hypothesis: a statement that can be (potentially) falsified. If it is not (potentially) falsifiable, then it isn’t scientific, and belongs to some other field. In the example given above, if I say that water boils at 100˚C, this is clearly scientific, as it can be proven false (or true) in an experiment. If I say that the earth was created by God, this clearly isn’t a scientific theory, because there is no way of testing this idea, and proving it to be false (or true).
The scientist/philosopher who advocated this idea was Karl Popper. In the 1960s he challenged what was then the accepted view that science worked along observationalist-inductionist lines – or, reaching conclusions about hypotheses on the basis of previous results, rather than the potential falsifiability of the idea. According to Popper, nothing that cannot be falsified can be called a scientific hypothesis/theory.
Some people have criticised Popper’s ideas, as it is difficult to show that some theories are false – for example, evolution. Indeed, Popper said of this:
Darwinism is not a testable scientific theory, but a metaphysical research program.
However, the idea of falsification being an integral part of a scientific theory is a very useful way of testing the validity of most scientific hypotheses, and separating the ones that have little claim to scientific legitimacy.
4. Are scientists always objective?
The scientific method is designed to be flawless system, protecting us not only from ‘bad science’, but also allowing ‘good science’ to emerge and flourish. How well it does this is open to interpretation. To form an opinion on this, read through this article on the climate change e-mail scandal.
- What does the article say about the peer review system?
- Why does the article say that there are ‘cracks in the system’?
- What is the University of East Anglia’s CRU and who heads it?
- What allegations have been made against him?
- If these allegations are true, what does it suggest about the scientific method?
- Research another scientific scandal, explaining what occurred, why, and the results.
- Do you think that scientists have any special ethical obligations that other professionals don’t have? If so, what are they, and why?
- Which element of our acquisition of knowledge in the natural sciences do you think is the most important? Why?
- How important is the role of reason in the process of knowledge acquisition in the natural sciences?
- Is the scientific method flawless?