Week 4: Popper

Question 1

Karl Popper

Answer 1

For Popper, the most important thing about science is that it is always critical. Scientists are always trying to prove their own theories false.

Question 2

According to Popper, which argumentation method do scientists use?

Answer 2

He thought that scientists only used deduction, but he was wrong.

Question 3

Falsification

Answer 3

Observation that shows that a theory is false.

Question 4

Falsified

Answer 4

State of a theory that has been shown to be false.

Question 5

Falsificationism

Answer 5

Popper’s claim that scientists are only interested in falsifying their own theories (wrong!).

Question 6

Pseudo-science

Answer 6

Some theories are so vague or flexible that they are worthless, but also the theories that do not make predictions.

Question 7

Simplified view of science

Answer 7

Scientists start from objective observations (things everyone can agree on). They also agree on how to test theories using these observations. Because of this, they can reach consensus (agreement) fairly easily.

Question 8

Confirmation and disconfirmation

Answer 8

Confirmation = when observations support a theory.
- If your theory is “All swans are white,” and you observe 10 white swans; that confirms the theory.

Disconfirmation = observations undermine a theory.
- If you then see one black swan, the theory is disconfirmed (proven wrong).

Question 9

The more confirming instances there are, the more believable the general statement becomes. But how many instances is enough? It depends on:

Answer 9

1. Expected uniformity: if we expect things to be mostly the same (like native speakers agreeing on grammar), fewer examples might be enough. If we expect a lot of variation (like different styles of painting), we’ll need more evidence.
2. Scope of the statement: a broad claim (e.g., “All animals feel pain”) needs more confirmation than a narrow one (“All cats in my house are friendly”).
3. Representativeness: the quality of examples matters. Random or biased examples don’t help much. Well-chosen, representative examples give stronger support.
4. Probability of the statement: if the claim is very unlikely, we’ll need stronger evidence to believe it.

Question 10

Why is the idea that science is purely objective and driven by data too simplistic?

Answer 10

Scientific theories are not just based on observations. Both confirmation and falsification (disproving theories) require a theoretical framework.

Question 11

Example of Deductive Logic (Valid Form):

Answer 11

All A are B.
x is an A.
Therefore, x is a B.

If all cats are mammals, and Fluffy is a cat, then Fluffy is a mammal.

Aristotle emphasised this kind of reasoning. The truth of the conclusion follows necessarily from the truth of the premises.

Question 12

Example of Invalid Deductive Form:

Answer 12

All philosophers are weird.
Victor Gijsbers is weird.

Therefore, Victor Gijsbers is a philosopher.

This doesn’t follow, because just being weird doesn’t prove you’re a philosopher.

Question 13

Problems with judging whether arguments are good:

Answer 13

1. If you disagree about logic and background information or theoretical framework, then you may also not agree about observations.
2. The way we interpret observations is influenced by our beliefs.

This means that the standard theory that observations and logic lead to theories that we agree on is not guaranteed to work.

Question 14

Why is the view (logic + observations → agreed-upon theories) too optimistic?

Answer 14

1. Logic isn’t always agreed on.
2. Observations are not always neutral: they are influenced by background beliefs.
3. Theories are not built in a vacuum, but within larger frameworks.

Question 15

Dogmatism

Answer 15

Popper opposed dogmatism, blindly sticking to beliefs without questioning them.

A healthy science (and society) should be based on criticism, not unchallenged beliefs.

Question 16

Pseudoscience vs. science

Answer 16

Pseudoscience can’t be tested in a way that could prove it wrong. Popper pointed to Freud’s psychoanalysis and Marxism as examples: they seem to explain everything in hindsight, but couldn’t be falsified by any observation.

Scientific theory can be tested and potentially proven wrong. Example: “Gravity causes objects to fall at 9.8 m/s² on Earth.” → Testable.

Question 17

Popper’s key points

Answer 17

1. Critical thinking is vital; don’t just seek confirmation.
2. Falsifiability separates science from pseudoscience.
3. Try to disprove your theory; not just support it.
4. Science progresses through bold theories that can be tested and possibly falsified.
5. But: this model doesn’t work equally well in humanities or complex, real-world science.

Question 18

Scientism

Answer 18

Believing that (natural) science is the only source of knowledge.

Question 19

Arguments in favour for scientism:

Answer 19

1. Science has been extremely successful.
2. Everything can be explained by or reduced to physics or the natural sciences.

Question 20

Arguements against scientism:

Answer 20

1. The natural sciences cannot explain or predict everything, or at least not in a way that is interesting or useful to us (e.g. art or literature).
2. The natural sciences lack normativity, which is something that we are interested in and would like to investigate (e.g. whether murder is good or bad).
3. Knowledge is more than just clear-cut facts, as in the natural sciences, it is also about understanding things and developing new ways of thinking (which is generally studied in the humanities).