Pigliucci and Boudry (2011) argue convincingly that the widespread use of machine metaphors in biology played into the hands of Intelligent Design advocates, because machines tacitly imply a designer or creator even if nothing of that sort is intended in the original analogy. Starting with Payley’s argument from design (watch on a heath), the main targets of Pigliucci and Boudry (2011) are machine metaphors for cells as factories and DNA as blueprint.
I agree with their claim that ID thrives on machine metaphors. However, abuse of analogies is not confined to machine metaphors. Formerly, organisms were infused with vitalistic forces and hence organism methaphors had the same problem. There may be some metaphors that can be less easily bent. For example, Tansley (1925, p. 24) regarded the mind as an organism, whereas it is only part of an organism. How would one abuse that?
In my opinion, the best way to deal with metaphors is to look at the orignal sources, see what was implied and what was not implied, and keep a differentiating perspective. Don't throw all machine metaphors into one pot.
In the context of proto ecosystem-ecology, for example, the first to fully exploit a machine analogy was Alfred J. Lotka in 1925. 'Fully exploit' means that Lotka did not just use a metaphor to enliven his writing or illustrate a point, but to justify the use of thermodynamics in biological research (Unfortunately, I do not have the 1925 original but only the 1956 imprint.)
Lotka reasons that thermodynamics is so general that it's laws apply to any energy transformer, living or mechanical. As thermodynamics has been developed using engines (mostly steam engines) the use of machine metaphors is just a way of saying that thermodynamic laws apply. The particulars of justifying the application of thermodynamics to biology are interesting, because they are the opposite of a myopic focus on mechanism.
“The first service of rendered by the laws of thermodynamics is thus a negative one, to save us from vain efforts to achieve the impossible. They tell us what we cannot do; they give us no guarantee as to what we can do, in this matter of engine efficiency. In other fields these same principles are, indeed, found competent to yield us information of most positive character, as the physicist and physical chemist knows from boundless wealth of example; the very fact that thy hold independently of substance and form lends to their application a catholicity hardly equalled elsewhere in science, and at the same time gives into our hands an instrument of the most extreme economy of thought, since we are relieved, in such application, of the necessity of treating each particular case, with all its complication of detail, on its own merits, but can deal with it by the short cut of a general formula. Still, the austere virtue of this impartiality with respect to substance and form becomes something of a vice when information is sought regarding certain systems in which mechanism plays, not an incidental, but the leading rôle.” (Lotka 1956, p. 327)
That means treating living systems as energy transformers allows the application of laws of thermodynamics and that in turn allows ignoring the details of the mechanisms of energy transformation in most cases. This is the exact opposite of the widespread hunch that machine metaphors are always employed in order to reduce organisms to mechanisms.
Additionally, Lotka’s analogy suggests the opposite of a designer or creator:
“The great world engine--in which each of us is a most insignificant little wheel--has its energy source, its firebox, so to speak in the sun, ninety-eight million miles away from the working substance (the "boiler"). From the engineer's stantpoint this would be an execrably bad design, if a high efficiency alone were the aim in view." (Lotka 1956, p. 331)
“The picture we must keep before us, then, is that of a great world engine or energy transformer composed of a multitude of subsidiary units, each separately, and all together as a whole, working in a cycle. It seems, in a way, a singularly futile engine, which with a seriousness strangely out of keeping with the absurdity of the performance, carefully and thoroughly churns up all the energy gathered from the source. It spends all its work feeding itself and keeping itself in repair, so that no balance is left over for any imaginable residual purpose.” (Lotka 1956, p. 335)
He continues with re-defining evolution as the development of that world engine towards greater efficiency, a notion, inherited from Spencer (Kingsland 1995, chap. 2), but the wold engine envisioned is an exceptionally absurd device ridiculing all claims of a creator.
Lotka's machine metaphor is not a trial to reduce organism to mechanism. On the contrary, it is a trial to get away from the gory details of mechanism and achieve a general treatment as in thermodynamics. Secondly, Lotka's world engine is an absurdity ridiculing, in retrospect, Intelligent Design notions.
- Lotka AJ (1956) Elements of mathematical biology. New York: Dover publications (first published as 'Elements of physical biology' in 1925).
- Pigliucci M, Boudry M (2011) Why machine-information metaphors are bad for science and science education. Science & Education 20:453-471.
- Tansley AG (1925) The new psychology and its relation to life. London: Allen & Unwin.