Sunday, January 31, 2010

Underdetermination, Prove it!

Positivist scientific philosophy, ala Popper, argues that scientific theories/statements can be judged through empirical experimentation and testing. If a theory/statement passes this test, usually by repeatedly and correctly predicting the outcome of a defined procedure, then scientists say that such a theory is factual. Or if they are very responsible, they say that it is provisionally true.

However, Post-positivists, as John Zammito calls them in his engaging history of SSK (Sociology of Scientific Knowledge) and STS (Science and Technology Studies) thought, have mounted several objections to this integral component of what is normally termed the Scientific Method.

What we can term the "underdetermination argument," is that recourse to experimentation to test scientific theories is simply insufficient to establish (or determine, hence the name) the level of credibility that is normally accorded to what we regard as scientific facts. It is always possible, and historically has usually been the case, that two (or more) theories which are logically incompatible, both adequately, at least at a certain point in history, explain a given set of empirical observations. In other words there is more going on, what Thomas Kuhn calls "historical accidents," when scientists determine "facts" than just some idealized Scientific Methodology.

Zammito acknowledges this point but only what he calls its "weak" form. Taken to its extreme the underdetermination argument could, and has by some authors, been used to relativise and thereby weaken Science's claim to be able to produce uniquely credible knowledge.

I tend to agree with Zammito on a pragmatic level, though I am not entirely convinced by the arguments he employs to avoid the slippery slope into relativism provided by the underdetermination thesis.



  1. Nice post.

    Can you cite a good example relevant to your standpoint on this matter? Then we can discuss more probably from there.

  2. Here is a very technical, and short, example of the basic idea (I stole it from Wikipedia).

    "According to Isaac Newton's mechanics, there is an absolute space in which events are located but all that can be detected are differences between velocities. Hence, it is equally consistent with this theory to say that the solar system is at rest, as it is to say that it moves at a velocity of 37 m/s in the direction from the center of the earth to the north pole. Newton himself indicated these two possibilities are indistinguishable."

    Also here is an ungated link ( to an article that looks at four empirically equivalent, but logically distinct, theories about general relativity.

    My interest in the underdetermination thesis, however, does not stem from a desire to relativise scientific findings. I'm not really interested in ontology. But I do find the thesis persuasive to the extent that it provides some justification for exploring the sociological aspects of scientific inquiry. To use the wikipedia example, why do we now generally prefer to state that the solar system is indeed moving at 37 m/s, rather than (as we did before Galileo and Copernicus) stating that the solar system is not moving? Newton's laws cannot give us guidance here, or again using the jargon, are underdeterminative.
    Unfortunately giving more concise examples is difficult because convincing/interesting sociological arguments require rather extended historical narratives.
    If you are curious however, I would recommend Shapin and Schaffer's "Leviathan and the Air Pump" which documents how much of what we now call the Scientific Method developed in response to specific historical, political, and cultural events that were occurring in 17th century Europe. If you want a more theoretical and less historical approach to the topic I would recommend Thomas Kuhn's "The Structure of Scientific Revolutions."