Philosophy of science investigates the nature of science. What should we count as science or non-science? What status should we place unobservable entities postulated by scientific theories? What kind of knowledge does science give us? And so on. In this tutorial, I will summarise Karl Popper’s theory of what demarcates science from non-science: falsification.
Falsification is the standard that demarcates science from non-science. This standard was put forward by Karl Popper. Hence, sometimes philosopher’s who argue for the falsificationist’s standard are called ‘Popperians’.
Falsification is the claim that in order for something to be viewed as science, it must involve putting forward an idea, a hypothesis, that can easily be shown to be false. The more easily it can be shown to be false, the more scientific it is, the more difficult it can be shown to be false, the less scientific it is. If it is impossible to be shown to be false, it is not scientific at all. In short, the hypothesis must be falsifiable (some scientists and philosophers will also call this being ‘testable’).
In addition to this, if the hypothesis is shown to be false, a scientific approach is either to discard the hypothesis as disproven, or produce a new hypothesis that explains why the the original hypothesis was apparently falsified. However, the new hypothesis must be more falsifiable than the original hypothesis.
A. F Chalmers (2013) gives a useful example of falsification in practice. The example Chalmers gives is the hypothesis that bread nourishes, but a French villiage experiences people dying from eating bread. If we put forward a new hypothesis ‘bread nourishes except in that French villiage’ is less falsifiable than the original theory. However, if we put forward a new hypothesis ‘bread nourishes except when contaminated with a particular germ or fungai’ is more falsifiable because this can be tested through looking at the French village’s bread for something specific about it that caused the people dying. If nothing can be found, then that hypothesis too would be falsified.
This falsification follows the logical form of Modus Tollens, which was discussed in the ‘conditionals’ tutorial:
-1. If hypothesis is true (p), then our prediction will be true (q)
-2. Prediction was not true (not q)
-3. Hypothesis is false (not p)
The reason Popper defends this model, is because if it is really easily for the prediction to be shown false, but consistently cannot, then it gives us more confidence that the hypothesis is true. This is the falsficationist’s view of science.
If you want to read about this in more detail, I recommend the book ‘What is this thing called Science?’ by A. F Chalmers, which is available in the link below: