Synthetic biology: there is no ‘life’

Last week in Nature, appears a peculiar editorial [1], entitled “Meanings of ‘Life’: Synthetic biology provides a welcome antidote to chronic vitalism.” It is a somewhat unsurprising coincidence that it appears almost on the same day as the Venter paper. Of interest are the following two remarkable assertions (bold added):

1)

There is a popular notion that life is something that appears when a clear threshold is crossed. One might have hoped that such perceptions of a need for a qualitative difference between inert and living matter – such vitalism – would have been interred alongside the pre-darwinian belief that organisms are generated spontaneously from decaying matter. Scientists who regard themselves as well beyond such beliefs nevertheless bolster them when they attempt to draw up criteria for what constitutes ‘life’. It would be a service to more than synthetic biology if we might now be permitted to dismiss the idea that life is a precise scientific concept.

2)

Synthetic biology’s view of life as a molecular process lacking moral thresholds at the level of the cell is a powerful one. And it can and perhaps should be invoked to challenge characterizations of life that are sometimes used to defend religious dogma about the embryo. If this view undermines the notion that a ‘divine spark’ abruptly gives value to a fertilized egg – recognizing as it does that the formation of a new being is gradual, contingent and precarious – then the role of the term ‘life’ in that debate might acquire the ambiguity that it has always warranted.

 

Assertion #1, that life is not a precise scientific concept and should therefore be dismissed, is premised on the false dichotomy of mechanism versus vitalism: either one must disavow the notion that a boundary between life and non-life is meaningful, or one runs the risk of being branded a ‘vitalist’. The idea that these two disparate views exhaust the solution space has long been known to be false. In 1929, theoretical biologist J. H. Woodger wrote in his book, Biological Principles [2]:

Among other factors which are responsible for the present impasse in regard to this antithesis [mechanism vs. vitalism] may be mentioned various vague beliefs about the necessity of the demands involved in the mechanistic position for the bare possibility of science, coupled with the notion that anything else is ‘mysterious’ and that there is no other alternative. I have already pointed out that those demands were framed in the mechanical interest in the first place, and their use will, accordingly, only lead to a mechanical result. If they are used blindly and intolerantly we are again only solving the problem dogmatically in advance of unprejudiced inquiry. And with regard to the belief that mechanism is the only alternative to mysticism it is only necessary to recall the words of J. S. Mill that in scientific explanation we only substitute one mystery for another. The choice is not between mechanism and mystery, but between one mystery and another. It is simply a question of whether the mysteries of physics can satisfy the requirements of theoretical biology, i.e., the systematization of biological knowledge.

Thus to ask “whether the mysteries of physics can satisfy the requirements of theoretical biology” is to pose an entirely scientific question about the comprehensiveness of contemporary physics. For the mechanist this question is inexplicably an intolerable affront, and for the vitalist the question is seemingly misconstrued as a launching point from which to exit science altogether. Yet, neither of these reactions is relevant to the question insofar as neither responds to the scientific question, the “unprejudiced inquiry”. It is a question which fundamentally seeks to probe and extend the borders of our scientific knowledge, yet neither mechanism nor vitalism has any capacity to bear it conceptually, much less operationalize the question into a program of investigation. To this extent, the mechanism/vitalism landscape is a starkly impoverished place. From such a landscape it can be seen how it is possible that assertion #1 can arise. For the mechanist, any “threshold” between living and non-living would require an attribute or property which does not exist within the boundaries of his paradigm and therefore must be seen as an invocation of vitalism – there is simply no other option open to the mechanist.

It has been shown repeatedly, e.g., [3], that the formalisms upon which contemporary physics rest possess numerous artefactual limits. These limits, which reside in the very mathematical language used to describe the material world, thereby place limits on the extent to which the material world can be modeled. This should be unsurprising, insofar as science has historically often required expansion in the formalisms used to model the material word as new properties and systems in the material world come under our scrutiny. It thus behooves us to consider the possibility that if we do not possess a precise concept of life working within the current formalisms, that perhaps it is the formalisms themselves which stand in the way of this advance. The mechanist might argue that such a venture is simply a waste of time, but the history of mathematics and science suggest otherwise, nor does the mechanist’s pessimism satisfactorily answer the issue of artefactual limits in formalisms.

Also, the suggestion that the concept of life be “dismissed” appears to also desire to dismiss away how the concept of ‘life’ has been, and continues to be, used to repeatedly and successfully divide systems in the natural world into the living and the non-living. Viewed as physical measuring devices, with sensory apparatus, discrimination and processing capacity, humans have been adept at making such measurements. These kinds of measurement successes cannot be ignored only on the basis of the material composition of the meters. Plainly, humans qua meters are measuring something in the material world. It is simply untenable to suggest that humans have been somehow mistaken or deluding themselves all along about ‘life’; that kind of skepticism quickly decays into solipsism. If we have uncertainties at the edges of our understanding of life (e.g., is a virus alive?), we should be unsurprised as this is beyond the normal resolution of humans qua meters. No, this uncertainty does not condemn the entire concept of life as one to be dismissed; rather, it compels us to investigate it further.

Assertion #2, predicated on assertion #1, argues that since there is no meaningful boundary between life and non-life, then there can be no meaningful moral difference between, say, tinkering with a toaster and tinkering with a bacterium. The editorial raises the assertion in the context of religious objections. Separate from that debate, there is the question of whether synthetic biology proposes to raise such an argument as a means of averting moral and ethical scrutiny over the potential dangers and misuses of such technology. Any material system which possesses a capacity to sustain, increase, and promulgate geographically, a population of such systems, possesses thereby an open-ended capacity to alter, interrupt and transmogrify the existing systems in the material world with which this population may interact, directly or indirectly. If the material system is a novel one, then there is no credible a priori means by which to predict, limit, and control those interactions. Definitional issues notwithstanding, if synthetic organisms possess a capacity to reproduce, it places them squarely on the other side of an moral/ethical threshold from the non-living.

 

References: 

[1] 06/27/07. “Meanings of ‘Life’: Synthetic biology provides a welcome antidote to chronic vitalism”. Nature. doi:10.1038/4471031b

[2] Woodger, J. H. 1929. Biological Principles. Routledge & Kegan Paul Ltd.

[3] Rosen, R. 1991. Life Itself. Columbia Univ. Press.

 

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2 Responses to Synthetic biology: there is no ‘life’

  1. Thanks for this extremely intelligent contribution to the discussion on the “meaning” of synthetic biology. As you rightly point out, we are not informed by a false dichotomy between “mechanistic” and “vital” interpretations of life.

    On the other hand, I think the distinction between living and non-living systems is still both pragmatically useful, and philosophically defensible — even if it is not absolute.

    My own curiosity about Life has led me to explore the consequences of human activity for the future of biological systems. In the course of that work, I have become impressed at the level of resistance our minds and culture seem to have in assimilating basic biological facts about ourselves into our self-identities.

    While forcing a choice between “vitalist” versus “mechanistic” interpretations of Life is false, I believe we are nonetheless greatly informed through the story of our evolutionary origins and history — and especially our inter-biological relatedness through time. Indeed, if our minds did not so clearly divide a space-time continuum into dimensions of space and time, but were rather inclined to see the two as one whole, then we might even claim that we are indivisible “parts” of one, unfolding, ever evolving life process — arising out of and fully dependent upon (and embedded within) the rest of the non-living universe.

    But very little of our culture accepts, much less seeks to reinforce, ideas of self that include such a perspective — indeed, quite the opposite is true. Yet curiously, being able to trace our identities back through an historically continuous process to a common point of shared ancestory does appear to be the biological fact of the matter for everything that is “alive” today.

    As for synthetic biology, the deepest question (at least as far as I can figure it) seems to me to be whether or not it is wise to promote the creation and inevitable environmental release of self reproducing systems that are NOT historically derivative of existing biological systems — i.e., they are wholly novel “lineages” of self-reproducing systems disconnected from the historical unity of the existing Living System. It seems to me that would risk creating evolving competitive lineages to “ourself” — the existing “lineage”.

  2. I find this editorial as peculiar as you say, and you are right to draw attention to it. The misconceptions that it embodies, however, are old, and formed the basis for Rosen’s strongly expressed dislike of Jacques Monod. The problem, as I see it, is that the reductionist approach brought biochemistry so far and so fast in the 100 years after Buchner that people find it hard to imagine that it won’t take it much further. Even though everyone can recognize a living system when they see one (as Maturana and Varela discussed), and in a sense, therefore, know that it is not just a machine, there is a great reluctance to recognize that there is a great an probably unbridgeable gap between the two. In the past half century or so remarkably few biologists have shown any interest in life, and if the editorialist in Nature is right (which I don’t believe) then they are right not to show any interest.