Skyhooks and Cranes
I’ve just started reading Angus Menuge’s book Agents Under Fire: Materialism and the Rationality of Science. In Chapter One (Title: Skyhooks and Cranes), Menuge references a “controversial metaphysical assumption” about what constitutes a scientific explanation in which one asserts that to understand a phenomenon one must identify the mechanism causally responsible. The “Crane” is the explanation based upon this mechanistic understanding of the phenomenon in question. Cranes are good, but “Skyhooks” are bad. By “Skyhook”, Menuge means an explanation with an appeal to non-mechanical agencies. The skyhook is an explanation that seems to be just dangling from the sky, not grounded in mechanical explanations. Actually, these are not Menuge’s terms, but are borrowed from Daniel Dennett and his discussion of proper scientific explanations. Much of the chapter discusses the reductionism which characterizes much of modern science. Cranes can be useful in demystifying phenomena such as human rationality. The cranes reveal that human rationality is merely (is reduced to) chemistry and physics such as the firing of neurons which arose in a purely naturalistic manner.
Menuge argues that the reductionist presents one with a false dichotomy in which one must choose “either (an) unscientific skyhook or (a) scientific crane.” At times, cranes have actually impeded scientific advances and the failures of these mechanistic reductions have actually resulted in great scientific advances. One should read the book to gain a better understanding of the full argument. Briefly, however, Menuge makes the following points regarding reductions in science:
1. Failed reductions, including the failure to provide a mechanism, do not necessarily mean a failure for science.
2. Successful reductions can be nonmechanistic.
3. Reductionist zeal can be bad for science.
Support for the above assertions are given from several examples. For one, the failure of Alchemist reductionism gave way to modern chemistry. If the alchemist had clung to his reductionism he would have been an obscurantist. Additionally, the Newtonian reduction of Kepler’s laws were not less significant because he did not offer a mechanism for his gravitational theory. Many actually resisted his scientific advances because his explanations appeared to be “skyhooks” instead of “cranes.”
Menuge summarizes:
“… Nonmechanical skyhooks can be very useful in science and mechanical cranes can be ideological figments. Mysterious skyhooks may shed a great deal of light, unifying and reducing other phenomena, whereas cranes may cast the whole world into darkness by denying the facts in front of our face.
Botched or overblown reductions can hinder science by obscuring realities that need to be explained. The identification of science with a favored reductionist program is a deplorable kind of scientism that prohibits the atmosphere of free inquiry and honest debate essential to true science.”