Proposals for Demarcation

(from readings in Curd & Cover, Philosophy of Science)

Confirmability

compare: the verifiability criterion of cognitive significance advocated by the logical positivists.

The positivists were interested in distinguishing empirical claims from "metaphysics." They held that the distinguishing characteristic of metaphysical claims was that there was no way to find evidence to support them. One of Ayer's examples: "the assertion that the world of sense-experience was altogether unreal" (LTL p. 39). It seems that no sensory experience could establish that all sense-experience is incorrect!

The positivists held that such claims were not cognitively significant (more colloquially, that they were meaningless). If no experience could confirm a claim, then the claim wasn't really an empirical one at all. Although they weren't specifically addressing the bounds of science, they would have been happy to conclude that such a claim could not be part of science.

Popper would probably agree that comfirmability is a necessary condition for a theory to be scientific. But he denies that it is sufficient. Popper's suggestion is that confirmation is way too easy to come by.

Popper's examples: astrology, Marx's theory of history, Freudian psychoanalytic theory, Adlerian psychology. His claim: adherents to these theories see confirmation everywhere. But this is precisely the problem with them: they are too easy to confirm! They are so easy to confirm that in fact they can't be disconfirmed: no matter what happens, there is a way to explain it in terms of the theory.

what does Popper mean by "confirmation," anyway? He seems to have in mind that a theory is "confirmed" if the following two things are true:

T -> O     (if the theory T is true, then a certain observable consequence O will obtain)
O             (O does in fact obtain)

But with theories that "explain everything," it may be that virtually anything we could observe can be "explained" in terms of the theory, that is, we can use the theory (after the fact) to construct a story about why O happened.

One thing this seems to miss is the role of prediction. If the theory is compatible with lots of possible observations, the it doesn't actually predict any of them.

Several possibilities here:

Popper makes the important observation that a test of a theory must be "risky." But why not make that a condition on confirmation, not a rejection of it altogether?

Popper's Proposal: Falsifiability

Popper's picture: a scientific theory can be falsified

T -> O
not O
Therefore, not T

But is falsification any more decisive than confirmation?

Kuhn's Proposal: Existence of puzzle-solving tradition

Kuhn: most scientific research is not aimed at confirming or falsifying a theory.

Rather, most research presupposes a theory and tries to use the theory to fill in detailed information that wasn't previously know, or to explain phenomena that it hasn't yet been applied to. In such cases the theory isn't being tested, but rather extended or applied.

Thagard's Proposal

"A theory or discipline which purports to be scientific is pseudoscientific if and only if:

  1. it has been less progressive than alternative theories over a long period of time, and faces many unsolved problems; but

  2. the community of practitioners makes little attempt to develop the theory towards solutions of the problems, shows no concern for attermpts to evaluate the theory in relation to others, and is selective in considering confirmations and disconfirmations."

Ruse's Proposal: The Grab-Bag Approach 

A discipline is more pseudoscientific the more of the following characteristics it has:



Last update: September 8, 2008
Curtis Brown | Philosophy of Science | Philosophy Department | Trinity University
cbrown@trinity.edu