Tag Archives: Logical Positivism

Telling science from pseudoscience and the demarcation problem

demarcPhilosophers of Science have long puzzled over what they call “the” demarcation problem, of how to distinguish science from pseudoscience. In the early 20th Century the Logical Positivists proposed the verification principle, that a statement was meaningful and scientific only if it could be empirically verified. Karl Popper then proposed a similar idea, that a scientific idea is one that can be falsified.

There is a lot of truth in both proposals, but neither can be interpreted too narrowly. The problem is that no statement can be verified or falsified in isolation. Science constructs whole webs of ideas, and it is the whole construct that is then compared to empirical data, to be adjusted and improved as necessary. Further, a statement such as Newton’s law of gravity can never be verified in the general sense, all we can say is that it worked well enough — as part of the wider web of ideas — in the particular instance we tested. Nor is it straightforward to falsify such a law. If our overall model is inconsistent with an observation then we could indeed alter one of the laws; but we might also overcome the inconsistency by altering some other part of the overall model; or we might doubt the reliability of the observations. Continue reading

A scientism defence of Logical Positivism

Like everyone else I read Ayer’s Language, Truth and Logic as a teenager and, like many people of a scientific bent, I loved it. The Logical Positivism that it espoused can be summarised as the claim that knowledge is of two types: (1) logical reasoning from axioms, such as used by mathematics; and (2) claims about the universe that can (in principle) be verified empirically. Anything else — such as metaphysics — is literally meaningless.

Language, Truth and Logic, by A. J. Ayer

Logical Positivism is generally held to have been refuted (following criticisms from notables such as Quine, Popper and others), and as stated in its original form that is a fair assessment. However, its general thrust can be defended as sound. Indeed, Logical Positivism was a forerunner of what today gets called scientism, and interpreting it as scientism it is very much alive.

First, a defender of scientism would subsume the first type of knowledge, the “logical reasoning from axioms”, into the knowledge that derives from empiricism and can be empirically verified. Afterall, the reason that we adopt our basic axioms of logic and mathematics is because they work — they give results that apply to our universe. Where else would we have got them from? Continue reading