20: Philosophy of Science:
The Problem of DemarcationSummary by: Jeff McLaren Last meeting we concerned ourselves with the scientific method. Since the time of Francis Bacon (1561-1626) and René Descartes (1596-1650) and for about 200 years after them, the scientific method was competing against authority to be considered as the best path to knowledge and truth. Today the scientific method has won that argument but with that victory came a new problem: almost every claim to knowledge claims to be scientific. How do we determine good science from bad science; real science from pseudoscience. This is known as the problem of demarcation.
Karl Popper
Popper believed that Einstein's theories in physics were scientific but that Freud's theories in psychology and Marx's theories in history were not. The crucial distinction was falsifiability. In Einstein's theories it is very clear what would falsify the theory – this is a scientific virtue. In Freud's and Marx's theories any fact could be twisted to give confirming evidence – this was a vice. Huge amounts of confirming data are not needed, are not important and actually are a distraction because achieving a proof positive result is not possible (the problem of universals). According to Popper, real science is concerned with trying to falsify hypotheses – if you are not trying to disprove a particular hypothesis then you are not doing science. For Popper a good scientific theory should be informative, surprising and initially improbable (that is falsifiability criteria must be clear). Good scientist must be very open-minded.
Other demarcation criteria:
1. Historical: Pseudosciences tend not to make much progress. But progress can be tricky to characterize, and hard to measure. Astrology has certainly changed over the centuries, and it’s plausible to claim that some of the changes constitute improvements. If a science were to correctly accounted for everything in its domain, it could not be expected to show any progress.
2.Comparison to rival theories: If a competitor makes substantial progress while the theory in question remains stagnant, then the un-progressive theory becomes pseudoscientific. This view has the consequence that a theory’s scientific status can change over time, without any change in the theory itself. Therefore theories that lack serious competitors, such as Newton's pyramidology are not pseudosciences.
3.Clear mechanical explanation: Pseudosciences, such as astrology, give no explanation of how the stars influence our lives. But many legitimate and successful theories lack mechanical accounts of crucial processes. Newton provided no physical mechanism for the action at a distance of gravity.
4.Social practice conception of science. A practice counts as scientific if the right people call it a science (and if its practitioners do the right sort of scientific things, such as publish journals and get jobs in universities). But this criterion counts institutionalized pseudoscience (for example, Lysenkoist biology in the former USSR) as scientific.
5.Pseudosciences have epistemically dubious origins, but genuine sciences, including chemistry, also originated in such dubious enterprises as alchemy, and almost all science ultimately arose from mythology and speculation.
Thomas Kuhn
He believed that actual scientific work is much less rational than commonly believed; it is driven less by data and more by scientists’ attachment to their theories, a paradigm: a consensus. Kuhn suggests that science can only be understood by studying how scientists actually work and have worked – not some idealized notion of 'Science'. He emphasizes the history of science, rather than its supposed logic. Kuhn thought he could explain why science is a uniquely successful way of investigating the world without crediting science with being as rational, cumulative, or progressive as had been thought. He presents evidence that most paradigm shifts are not rational but rather are more like religious conversions. He further claims that any set of rules for the demarcation of science can be shown to be detrimental to the advance of science in history had the demarcation criteria been in effect. In other words: any definition of what is good science would have prevented at least one historical paradigm shift. Therefore, science should not be defined exactly because we may inadvertently be limiting its future growth.
Questions
1. Is the difference between science and pseudoscience a matter of kind or degree? Or both?
2. Would Popper consider biology, psychology, economics, history, astrology or sociology as scientific? Do you agree or disagree?
3. Should we accept Popper's idea that lots of confirming evidence and wide explanatory scope are not virtues of a scientific theory?
4. If we believe that science is only the act of trying to disprove a hypotheses, what then is the process of hypothesizing?
5. What would be the implications of deciding that astrology is better described as lousy science than as pseudoscience?
6. In Popper's view what is the difference between modern physics (with ideas such as dark energy/matter, black holes, string theory) and astrology (with ideas that planets can affect our lives)?
7. Kuhn asks us to resist the temptation to find a solution to the demarcation problem. Do you think we should leave 'science' undefined?
8. Do you think that normal science is as dogmatic as Kuhn says it is, or as open-minded as Popper says it is, or somewhere in between?
9. In considering conditions under which you think scientists should reject central and widely accepted hypotheses (such as the fundamentals of evolution by natural selection or of plate tectonics)? How significant is the ease or difficulty with which this task is accomplished?
10. Which is better for society: to have a very dogmatic and unitary science or to have a more revolutionary and open science? Are there groups who would benefit one way or the other?
11. What values would be associated with each extreme in question 10?
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