07 January 2012

Paragraphs to Ponder

From Mark Crovelli, on science and the scientific method:

If even one member of the scientific community were omniscient, it would be possible to appeal to that member as an objective assessor of scientific theories. In that case, the omniscient assessor would not trouble himself with describing the world using the clumsy word "theory," however. He would say "the world works thusly," or "the world does not work thusly." If such a person existed, moreover, the practice of "science" would cease altogether, because certain knowledge about the world could be obtained from the omniscient person without the need to tediously and imperfectly study the world "scientifically."
Because the scientific community does not count omniscient members among its number, its members have developed a "scientific method" to try to deal with their uncertainty about their theories. The "scientific method," which consists of developing hypotheses and "testing" those hypotheses against empirical experience, does not provide the scientific community with certain knowledge, however. It merely serves a rather low hurdle that assists in weeding out what most scientists would consider implausible, unverifiable, and silly theories.
A theory's ability to clear this low hurdle by no means can be interpreted as "verifying" a theory, or "proving" its truth, however, because alternative theories could always be imagined that would also be consistent with the empirical "facts." The scientific method does not provide the scientific community with a means to determine which theory, if any, out of the limitless set of alternative theories that could be dreamed up to explain the same empirical phenomena is "correct." Nor does the scientific method provide the scientific community with a means to know for certain that its members are not misinterpreting the empirical evidence. Only an omniscient being could know these things for certain.
Because empirical evidence does not "speak for itself," and because scientists are not omniscient (and thus cannot know if they are "correctly" interpreting empirical evidence), scientists can never know for certain if their theories correctly describe physical reality. This means that any theory that relies on the interpretation of empirical evidence can never be more than a subjective statement of belief about how a part of the world works, based on some empirical evidence.
This definition is unavoidable, because no scientist is in an omniscient position to know for certain whether he has interpreted empirical evidence correctly, or whether his theory is the "correct" one out of the infinite set of alternative theories that could be imagined to explain a given phenomenon.
This is not to say that scientific theories that rely on the interpretation of empirical evidence are useless or meaningless, simply because they are subjective statements of belief. Nor does it imply that all empirically derived scientific theories are equally plausible, or that they all must be deemed "equal" in some other way, simply because they are all subjective statements of belief about how the world works. On the contrary, a theory that relies on empirical evidence is nothing more than an "expert opinion" about how a part of the world works, but it can nevertheless be useful — sometimes amazingly useful, in fact — even when it is known to be "incorrect" in some respects (e.g., Newtonian physics). Moreover, individuals are free to evaluate the plausibility of scientific theories on their own, which means that they are free to accord some empirical scientific theories more plausibility than others.

The whole thing is very much worth a read, and paints a perfect picture of the limits and value of science.

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