structure for 'Science'    |     alphabetical list of themes    |     unexpand these ideas

14. Science / B. Scientific Theories / 5. Commensurability

[possibility of comparison between theories]

10 ideas
Many different theories will fit the observed facts [Bacon]
     Full Idea: The ordinary face and view of experience is many times satisfied by several theories and philosophies.
     From: Francis Bacon (The Advancement of Learning [1605], II.VIII.5)
     A reaction: He gives as his example that the Copernican system and the Ptolemaic system both seem to satisfy all the facts. He wrote in 1605, just before Galileo's telescope. His point is regularly made in modern discussions. In this case, he was wrong!
Two goods may be comparable, although they are not commensurable [Ross]
     Full Idea: It may be that two orders or classes of good things are not commensurable, though they are comparable, with those in the other.
     From: W. David Ross (The Right and the Good [1930], §VI)
     A reaction: This refers to moral issues, but seems helpful when faced with Kuhn's claim that Newton and Einstein are 'incommensurable'. We could hardly prefer one theory to another if we couldn't compare them.
We lack frames of reference to transform physics, biology and psychology into one another [Goodman]
     Full Idea: We have no neat frames of reference, no ready rules for transforming physics, biology and psychology into one another.
     From: Nelson Goodman (Ways of Worldmaking [1978], 1.2)
In theory change, words shift their natural reference, so the theories are incommensurable [Kuhn]
     Full Idea: In transitions between theories words change their meanings or applicability. Though most of the signs are used before and after a revolution - force, mass, cell - the ways they attach to nature has changed. Successive theories are thus incommensurable.
     From: Thomas S. Kuhn (Reflections on my Critics [1970], §6)
     A reaction: A very nice statement of the view, from the horse's mouth. A great deal of recent philosophy has been implicitly concerned with meeting Kuhn's challenge, by providing an account of reference that doesn't have such problems.
Kuhn has a description theory of reference, so the reference of 'electron' changes with the descriptions [Rowlands on Kuhn]
     Full Idea: Kuhn and Feyerabend adopt a description theory of reference; the term 'electron' refers to whatever satisfies the descriptions associated with electrons, and since these descriptions vary between theories, so too must the reference.
     From: comment on Thomas S. Kuhn (Structure of Scientific Revolutions (2nd ed) [1962]) by Mark Rowlands - Externalism Ch.3
     A reaction: This is a key idea in modern philosophy, showing why all of reality and science were at stake when Kripke and others introduced a causal theory of reference. All the current debates about externalism and essentialism grow from this problem.
Incommensurability assumes concepts get their meaning from within the theory [Kuhn, by Okasha]
     Full Idea: The doctrine of incommensurability stems from Kuhn's belief that scientific concepts derive their meaning from the theory in which they play a role.
     From: report of Thomas S. Kuhn (Structure of Scientific Revolutions (2nd ed) [1962]) by Samir Okasha - Philosophy of Science: Very Short Intro (2nd ed) 5
     A reaction: Quine was the source of this. Kripke's direct reference theory was meant to be the answer.
Galileo's notions can't be 'incommensurable' if we can fully describe them [Putnam on Kuhn]
     Full Idea: To tell us that Galileo had 'incommensurable' notions and then go on to describe them at length is totally incoherent.
     From: comment on Thomas S. Kuhn (Structure of Scientific Revolutions (2nd ed) [1962]) by Hilary Putnam - Reason, Truth and History Ch.5
     A reaction: How refreshingly sensible. Incommensurability is the sort of nonsense you slide into if you take an instrumental view of science. But scientists are continually aim to pin down what is actually there. Translation between theories is very difficult!
If theories are really incommensurable, we could believe them all [Newton-Smith]
     Full Idea: If theories are genuinely incommensurable why should I be faced with the problem of choosing between them? Why not believe them all?
     From: W.H. Newton-Smith (The Rationality of Science [1981], VII.1)
One may understand a realm of ideas, but be unable to judge their rationality or truth [O'Grady]
     Full Idea: It is possible to conceive of one understanding the meaning of a realm of ideas, but holding that one cannot judge as to the truth or rationality of the claims made in it.
     From: Paul O'Grady (Relativism [2002], Ch.5)
     A reaction: I think Davidson gives good grounds for challenging this, by doubt whether one 'conceptual scheme' can know another without grasping its rationality and truth-conditions.
Two things can't be incompatible if they are incommensurable [Okasha]
     Full Idea: If two things are incommensurable they cannot be incompatible.
     From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 5)
     A reaction: Kuhn had claimed that two rival theories are incompatible, which forces the paradigm shift. He can't stop the slide off into total relativism. The point is there cannot be a conflict if there cannot even be a comparison.