Philosophy of science 134E
Instructor: Christian Lacroix
Nov. 16, 2004
Science and Pseudoscience
Imre Lakatos (1922-1974)
Hungarian-born British philosopher of science
Originally a radio lecture given in 1973.
Offers a retrospective on the demarcation problem
Argues for a solution to the demarcation problem by using the notion of research program.

How to solve the demarcation problem
A simple proposal: Define knowledge as whatever is believed strongly enough by sufficiently many people.

Problem: In history, many people were totally committed to absurd beliefs.
E.g., demons, angels, devils, heaven and hell.
By contrast, scientists are very sceptical even of their best theories.
No degree of commitment to beliefs makes them knowledge.

On the scientific value of a theory
The value of a theory has nothing to do with its psychological influence on people’s minds.
The strength of belief in it, the amount of commitment, is irrelevant.
Its scientific value of a theory depends only on what objective support it has in facts.

Science is based on facts
What does that mean?
17th century witchcraft was based on a lot of observations and experiments.
Newton claimed that his theory was only based on facts (gathered by Kepler), but this is obviously wrong.
E.g., Kepler’s elliptical orbits vs. Newton’s perturbation theory

Science is based on facts?
The problem of induction: There can be no valid derivation of a law of nature (universal statement) from a finite number of facts.
Yet, we still hear about scientific theories being proven by fact.
That’s because our concept of scientific knowledge derives from 17th century theology’s concept of knowledge, where errors are sins.  

From certainty to probability
All scientific theories are equally unprovable.
To solve the demarcation problem, many sophisticated inductivists (‘inductive logicians’) tried to use probability:
If the mathematical probability of a theory is high, it qualifies as scientific, if low or zero, it is not scientific.
Probabilism
Good point of probabilism:
Give a continuous scale from poor theories with low probability to good theories with high probability.
Problem with probabilism:
Popper argued that the mathematical probability of all theories, scientific or not, given any amount of evidence, is zero.

From probability to falsification
Popper’s solution to the demarcation problem:
A theory is scientific if we can specify falsifiable consequence, and non-scientific is we cannot (or are unwilling).

Falsificationism
The scientific status of a theory is independent of the facts. 
It depends on the scientists attitude toward it: whether they are willing to specified under which condition the theory could be refuted.
Problem: Scientists are committed to their theory, and they are willing to tolerate a fair amount of ‘anomalies’.

From falsification to paradigm change
Kuhn’s view: a scientific revolution is just an irrational change in commitment, akin to a religious conversion.
Good points:
It better fits the history of science.
It explains scientists’ commitment to their theory.
Bad consequences:
No clear demarcation between science and pseudo-science.
No distinction between scientific progress and intellectual decay.
No objective standard of honesty.

From paradigm to research program
Lakatos’ own view:
Scientific progress is best described in terms of research programme, not in terms of single hypothesis.
Individual statements (e.g., all swans are white) can be easily proved false, but this kind of “trial and errors” method is not science.

A research programme includes:
A hard core
Tenaciously protected from refutation
Auxiliary hypotheses
More flexible protecting belt
A heuristic
A powerful problem-solving machinery

Some examples of research programmes: Newton’s gravitation, Einstein’s relativity, quantum mechanics, Marxism, Freudianism.
All have a hard core, auxiliary hypotheses, and a heuristic.
All have, at any given time in their history, a bunch of unsolved problems.
In a way, they are all refuted.

To have a research programme is not enough to be good science.
What distinguish a scientific or progressive research program from a pseudo-scientific or degenerative one?

Contrary to Popper, it is not a matter of being refuted or not.
Rather, it is a matter of predicting novel and unexpected facts.
Facts completely undreamed of;
Facts that go against previous or rival RPs.
E.g., Halley’s prediction of a comet’s return in 72 years.

In a progressive research programme, theories lead to new and unexpected discoveries.
In a degenerative research programme, theories only account for known facts.

The scientific status of a research programme does not depend on confirmation.
Popper is right that confirmation is all too easy to get.
So Lakatos’ view goes against the sophisticated inductionists.

The scientific status of a research programme does not depend on being falsifiable but not yet falsified.
All research programmes face some anomalies, yet are not abandoned.
There is no crucial experiment.
So Lakatos’ view goes against Popper’s falsificationism.

If scientific revolutions are not brought about by falsification, does it mean that they are irrational (as Kuhn says)?

The rational of scientific revolutions is that scientists tend to prefer progressive research programmes over degenerative ones.
Kuhn is wrong that scientific revolutions are sudden, irrational changes in vision.
Thus Lakatos’ view goes against Kuhn’s.