Saturday, December 22, 2007

No, science does not 'rest on faith' by AC Grayling

reposted from:
Chris Street comments are in bright green;
highlights in yellow blockquotes.

In A recent opinion piece in The New York Times,

physicist Paul Davies asserts that it is a mistake to distinguish science from religion by describing the former as based on testable hypotheses while the latter is based on faith. "The problem with this neat separation," he says, "is that science has its own faith-based belief system."

Davies does not seem especially clear about what he means by this. He begins by describing scientific faith as "the assumption that nature is ordered in a rational and intelligible way", but soon shifts to describing it as "belief in the existence of something outside the universe, like... an unexplained set of physical laws". Either way, the failure or refusal to explain the source of physical laws is, he says, to regard nature as "rooted in reasonless absurdity".

The brevity of the piece does not allow

Davies - who won the Templeton prize for progress towards spiritual discoveries - to offer his now familiar suggestion that the universe is "self-conscious" or contains a "life principle" which obliges the laws of physics to take a form necessary for the existence of intelligent life.

There are half a dozen competing suggestions, most of them better than this one, as to why the universe's (or this universe's) parameters are as they are. Even the one that says "it is just a bald fact that they are so" does not deserve Davies's tendentious description of them as a commitment to "reasonless absurdity". It is a perfectly consistent possible truth that seems unsatisfactory only to the pattern-seeking, reason-requiring impulse with which evolution has endowed the human mind.

Davies could also not be more wrong in describing science's assumption that the universe is orderly and intelligible as an "act of faith". Patterns and regularities are a salient feature of nature, even to casual observation, and well motivate the assumption that they hold generally, or that when they fail to hold they do so for likewise orderly reasons. Once thus made, the assumption is then powerfully justified by the success of making testable predictions that are based on it.

Making well-motivated, evidence-based assumptions that are in turn supported by their efficacy in testing predictions is the very opposite of faith. Faith is commitment to belief in something either in the absence of evidence or in the face of countervailing evidence. It is seen as a theological virtue precisely for this reason, as the story of Doubting Thomas is designed to illustrate. In everyday speech we use the phrase "he took it on faith" to mean "without question, without examining the grounds"; this captures its essence.

If the assumption of nature's orderliness frequently or haphazardly failed to be borne out we would register the fact, supposing we survived the mistake in the first place. True, this amounts to offering inductive support for induction; but this does not mean that the circle cannot be explanatory, as shown by the fact that

it is a mark of irrationality not to rely on the success of past inductions in a present one. To see why, imagine saying: "Every time I have been out in the rain without an umbrella in the past I have got wet; but inductive reasoning is fallible, so perhaps this time I will stay dry."

If the assumption of nature's orderliness were not borne out, we would register it

The public and repeatable testing of hypotheses distinguishes science as the most successful form of inquiry ever. Among other things it shows that it is officially not in the business of accepting anything "without question, without examining the grounds". Davies and others who describe science as "ultimately resting on faith" are thus not only wrong but do much irresponsible harm to it thereby.

From issue 2633 of New Scientist magazine, 08 December 2007, page 55

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