Criticisms of Popper’s falsificationism

1) Popper is too strict. Sometimes it makes sense to allow ad hoc changes. Even though the origin of theories may be conjecture, young theories need to be developed and perfected. Some ad hoc changes end up being useful and good.

2) Doesn’t tell us anything about how science proceeds most of the time. Focuses too much on times when there are big changes in science and not enough on the day to day practice of science. We will talk about this next class when we switch to Kuhn.

3) Hypotheses aren’t ever really falsified. This is what we will focus on today.

4) …

Quine

Hypotheses aren’t ever really falsified.

The logic of Popper’s falsificationism works like this:

If H then O
~O
~H

If I translate these symbols into words they mean “If the hypothesis is true then I should be able to make a particular observation. I don’t/can’t make the observation. Therefore the hypothesis is not true.”

This is a valid deductive argument. I could fill in H and O with many different theories and observations.

H = Mary is a good student
O = Mary gets an A on the test

Or

H = Antarctica goes through periodic warming cycles
O = You find fossils of plant life in Antarctica

But, have you every seen a case in which a good student didn’t get an A on a test? What could be going on in that sort of case?

A problem is Popper is that he assumes that we can relate a hypothesis (H) directly to an observation (O), and this is not the case. Really, we need to specify initial conditions (IC) and likely some auxiliary hypotheses (AH) as well.

H = Mary is a good student
O = Mary gets an A on the test
IC = Mary took the test
AH = the test was a good indication of Mary’s intelligence.

H = Antarctica goes through periodic warming cycles
IC = You were actually in Antarctica looking for fossils
AH = Fossil evidence gives indication of historical background
O = You find fossils of plant life in Antarctica

When we add IC and AH to the argument, it looks like this:

If (H & IC & AH) then O
~O
~H

This is the basic pattern that the falsificationist method relies on.

But, this is actually invalid. What can be validly derived from the premises?

If (H & IC & AH) then O
~O
~(H & IC & AH) which means ~H or ~IC or ~AH

That is... The hypothesis could be false, we could have the initial conditions wrong, or we could have made a mistake in an auxiliary hypothesis, or and set of the three could be the source of the problem. It is always possible to blame the IC or AH rather than the theory.