Thursday, March 30, 2006

Polanyi on the Membrane

Yesterday I wandered--via Phil Mullins via Peirce's Lectures on Pragmatism via Clark via something more recent by Clark--through the environs of the Polanyi Society. Browsing through some recent issues of the Society's journal, Tradition & Discovery, the idea of the "morphogenetic field" jumped out at me. I'm not able to clarify any issues of debate between Polanyi scholars on how this should be understood; I'm merely discovering (rediscovering, as the case may be) the morphogenetic field for myself, and ruminating on it.

The Society has brought together some of Polanyi's essays, fortunately for me, since I don't have any of Polanyi's books in my personal library. I started with Life's Irreducible Structure, which does indeed touch on a notion of morphogenetic fields. An Excerpt (footnotes omitted):

This missing principle which builds a bodily structure on the lines of an instruction given by DNA may be exemplified by the far-reaching regenerative powers of the embryonic sea urchin, discovered by Driesch, and by Paul Weiss’s discovery that completely dispersed embryonic cells will grow, when lumped together, into a fragment of the organ from which they were isolated. We see an integrative power at work here, characterized by Spemann. and by Paul Weiss as a “field”, which guides the growth of embryonic fragments to form the morphological features to which they embryologically belong. These guides of morphogenesis are given a formal expression in Waddington’s “epigenetic landscapes”. They say graphically that the growth of the embryo is controlled by the gradient of potential shapes, much as the motion of a heavy body is controlled by the gradient of potential energy.

Remember how Driesch and his supporters fought for recognition that life transcends physics and chemistry, by arguing that the powers of regeneration in the sea urchin embryo were not explicable by a machinelike structure, and how the controversy has continued, along similar lines, between those who insisted that regulative (“equipotential” or “organismic”) integration was irreducible to any machinelike mechanism and was therefore irreducible also to the laws of inanimate nature. Now if, as I claim, machines and mechanical processes in living beings are themselves irreducible to physics and chemistry, the situation is changed. If mechanistic and organismic explanations are both equally irreducible to physics and chemistry, the recognition of organismic processes no longer bears the burden of standing alone as evidence for the irreducibility of living things. Once the “field”-like powers guiding regeneration and morphogenesis can be recognized without involving this major issue, I think the evidence for them will be found to be convincing.

There is evidence of irreducible principles, additional to those of morphological mechanisms, in the sentience that we ourselves experience and that we observe indirectly in higher animals. Most biologists set aside these matters as unprofitable considerations. But again, once it is recognized, on other grounds, that life transcends physics and chemistry, there is no reason for suspending recognition of the obvious fact that consciousness is a principle that fundamentally transcends not only physics and chemistry but also the mechanistic principles of living beings.

And a detour. Pierce cites the maxim Generale est quod natum aptum est dici de multis. The version I am using omits Peirce's footnote--quelle horrible--so I'm in danger of losing the source to the principle of In Googlis non est, ergo non est. File under Z for zettel until further notice.

posted by Fido the Yak at 2:32 PM.


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