Sunday, December 16, 2007
A Matter of Some Gravity
I'm currently picking my way through Norman Kemp Smith's classic study, The Philosophy of David Hume. One of the major influences on Hume was Newton's formulation of the experimental method, which rejected the use of hypotheses, except as subservient explanations of properties already discovered or to suggest further experiments. That formulation was to prove too restrictive, especially outside the relatively simple confines of the physics of Newton's time. That doesn't mean he was all wrong, of course.
Newton, naturally enough, bristled when it was suggested that gravity was a hypothesis. Instead, Newton held that gravity, along with other "principles" or "phaenomenon" such as mass and inertia, are "ultimate characters" of bodies, learned directly from experience. They are "manifest" because they are properties that can be observed experimentally. Newton makes no attempt to explain the ultimate nature of gravity, which may or may not rest on more basic properties of matter. But gravity is an ultimate phaenomenon as far as we are concerned.
The contrary to phaenomenon is the "occult," that which is not manifest and is, instead, secret or hidden. As Newton explained in the Opticks:
[T]he Aristotelians gave the name of occult qualities, not to manifest qualities, but to such qualities only as they supposed to lie hid in bodies, and to be the unknown causes of manifest effects: Such as would be the causes of gravity, and of magnetic and electric attractions, and of fermentations, if we should suppose that these forces or actions arose from qualities unknown to us, and uncapable of being discovered and made manifest. Such occult qualities put a stop to the improvement of natural philosophy, and therefore of late years have been rejected. To tell us that every species of things is endowed with an occult specific quality by which it acts and produces manifest effects, is to tell us nothing: But to derive two or three general principles of motion from phenomena, and afterwards to tell us how the properties and actions of all corporeal things follow from those manifest principles, would be a very great step in philosophy, though the causes of those principles were not yet discovered: And therefore I scruple not to propose the principles of motion abovementioned, they being of very general extent, and leave their causes to be found out.The Intelligent Design Creationists attempt to make this sort of distinction. For instance, Michael Behe, in Darwin's Black Box, says (p. 197):
The conclusion that something was designed can be made quite independently of knowledge of a designer. As a matter of procedure, the design must first be appreciated before there can be any further question about the designer. The inference to design can be held with all the firmness that is possible in this world, without knowing anything about the designer.Quite apart from the silly claim that knowing the means and motives of a possible designer (i.e. humans, the only designer we have experience of) can't aid in the identification of human artifacts, the problem with ID's contention is that design is not "manifest" in biology, a fact that Darwin established by showing how adaptation (and non-adaptation) can arise spontaneously out of the processes of life. Instead, IDers have to hunt for their claimed examples of design here and there in the nooks and crannies of minutia like the flagellum, the very opposite of the manifest laws of the universe "of very general extent" that Newton discovered.
Instead, ID puts a stop to the improvement of our scientific knowledge. To tell us nothing more than that living things have an occult specific quality called "design" by which manifest effects of biology are produced, is to tell us nothing ... except, that is, something about the religious beliefs of the proponent.