PHIL 0610 Philosophy and Science Handout #4
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PHIL 0610
Philosophy and Science
Handout #4
Popper – Conjectures and Refutations
I. The demarcation problem
Popper begins by stating that the problem that has interested him most throughout his career has been not which scientific theories are true, but what counts as a scientific theory. This is known as the demarcation problem.
The demarcation problem is the problem of distinguishing between what counts as science and what doesn’t. Sometimes people frame that problem as distinguishing between science and pseudo-science, but not everything that is not science is pseudo-science.
One intuitive way of separating science from non-science is by means of the methods involved. Popper says that you might hope to distinguish science from non-science by giving the following account of science: science is characterized by its empirical method, which is essentially inductive, proceeding from observation or experiment.
Popper thinks this is unsatisfying. He thinks that this just pushes the problem down to the level of “empirical method.” Now we need to specify in more detail what distinguishes a genuinely empirical method that involves observation or experimentation from a method which does involve observation or experimentation, but which doesn’t amount to science. For example, Popper thinks that astrology does involve empirical methods of some kind, but that it fails to reach the level of a science.
II. A very brief and simplified version of two theories
Popper started thinking about the demarcation problem as a result of comparing the new (at the time) and exciting ideas in Einstein’s gravitational theory, Adler’s individual psychology, Freudian analysis and Marxist theory of history. While the first seemed like a science to Popper, the other three did not. Let’s take a brief look at two of the theories.
1. Einstein’s theory of gravitation
According to Newtonian mechanics, gravitation is a force of attraction between two bodies that depends on how massive each body is and the distance between them. Instead, Einstein’s theory said that space and time are woven together into a single continuum known as space-time. Massive objects, in this theory, cause a distortion in space-time. Here is a helpful analogy using trampolines:
‘Imagine setting a large object in the center of a trampoline. The object would press down into the fabric, causing it to dimple. If you then attempt to roll a marble around the edge of the trampoline, the marble would spiral inward toward the body, pulled in much the same way that the gravity of a planet pulls at rocks in space.’1
2. Adler’s individual psychology
Adler’s individual psychology was strongly influenced by Freud, but instead of positing the primary human drive as sex and libido, Adler proposed that humans are primarily driven by a desire for superiority and power:
‘[Adler’s individual psychology] held that the main motives of human thought and behavior are individual man’s striving for superiority and power, partly in compensation for his feeling of inferiority. Every individual, in this view, is unique, and his personality structure—including his unique goal and ways of striving for it— finds expression in his style of life, this life-style being the product of his own creativity. Nevertheless, the individual cannot be considered apart from society; all important problems, including problems of general human relations, occupation, and love, are social.’2
Popper observed claims of confirmation for both theories:
In 1919, the astronomer Eddington’s eclipse observations provided confirmation for Einstein’s theory. If Einstein’s theory was correct, the mass of the sun should bend the light of stars passing near it. During an eclipse, the sky is dark enough to observe stars behind the sun. Eddington’s team took photos of stars near the sun during the eclipse and compared the photos to the same stars when they were not in proximity to the sun. The results showed the expected bending of light, confirming Einstein’s theory.
Popper had personal interactions with Adler. Popper described to him a case of a particular child and Adler explained to Popper how this particular case accorded with his theory. When Popper asked Adler how he could be sure, Adler replied that his theory had been confirmed by thousands of cases of clinical experience.
Popper concluded that it was the ease of confirmation of the three theories that made him doubt they were science. The proponents of the three theories seemed to take every observation as confirmation of the theory. In contrast, if Eddington’s eclipse observations had turned out otherwise, it would not have confirmed Einstein’s theory. Popper concluded that the hallmark of a genuinely scientific theory is that it is incompatible with certain possible results of observation. (p.266)
III. Falsificationism
This led Popper to the following conclusions about theories:
1. Almost every theory can be confirmed through observation.
2. Confirmations should only count if they are the result of risky predictions. Risky predictions are those proposed by a theory that are in conflict with what we would expect without the theory (e.g., bending of light from stars).
3. Every “good” scientific theory forbids certain things from happening. The more it forbids the better!
4. A theory that is not refutable by any conceivable event is not scientific.
5. Every genuine test of a theory is an attempt to falsify it.
6. Confirming evidence should not count except when it can be presented as a serious but unsuccessful attempt to falsify the theory.
7. Rescuing a theory through ad hoc assumptions when it seems to have been refuted lowers its scientific status.
The upshot of these conclusions—Popper thinks—is that we can determine what constitutes a scientific theory on the basis of falsification.
Falsificationism: A hypothesis is scientific if and only if it has the potential to be refuted by some possible observation.
According to Popper’s picture, a theory is scientific if it is falsifiable. Take any theory and deduce an observational prediction from it. We can check to see if the prediction comes out as the theory predicts. If it doesn’t, the theory is refuted. If it does, Popper thinks this doesn’t tell us anything. The theory is not confirmed, nor more likely than before. The best we can hope for according to Popper’s falsification is that a theory has not been falsified (yet)!
Question: Does Popper’s falsification criterion distinguish science from non-science in the way we’d expect?
IV. Guide for the next reading: Salmon “Rational Prediction”
Salmon’s paper is not too long and is pleasingly clear. Salmon argues that Popper’s conception of a scientific theory entails that it can’t provide predictions and is therefore not helpful.
2023-02-18
Popper – Conjectures and Refutations