The Pattern which Connects Pleroma to Creatura: The Autocell Bridge from Physics to Life

by Terrence Deacon and Jeremy Sherman


By his own standards Gregory Bateson was unsuccessful in his life-long quest to explain how the informational or living realm (creatura) could emerge out of the energetic or physical realm (pleroma). Drawing upon recent insights in self-organization theory, the authors suggest a missing link connecting the realms; a simple spontaneously­arising, non-living, yet evolvable molecular system called an “autocell” consisting of the reciprocal linkage between an autocatalytic cycle and a self-assembling encapsulation process (modeled on viral encapsulation) where the molecular constituents for the capsule are products of the autocatalysis. Autocells are shown to have the rudiments of individuality, end-directedness, function, and valuation; thus bridging the critical initial gap between pleroma and creatura.



In a previous paper in this volume, Ty Cashman calls our attention to Gregory Bateson’s abiding, yet ultimately unanswered question: What connects creatura to pleroma, the realm of life to the realm of non-life, the informational realm to the energetic realm, mind’s realm to matter’s realm? This is not, however, a division that the majority of scientists and philosophers today recognize as particularly troublesome. Since Descartes, Western traditions have focused on the split between soul and body, consciousness and biology. But to Bateson, evolution and learning were contiguous and the distinguishing features of mind were evident in all living processes. For him, the critical “epistemic cut” was identified between energetic and informational processes, and since life has at its base an informational character the crucial distinction must be drawn at the life / non-life transition. Though he never directly attempted to address questions about this transition, understanding the pattern of causality that connects non­life to life, physics and chemistry to biology, is implicitly the core mystery that stands behind his larger enterprise. While many, if not most of our colleagues remain more interested in the emergence of consciousness, and treat the emergence of biology from chemistry as a nearly solved problem, we believe that Bateson’s insight points to an unrecognized fallacious presumption in this viewpoint: that life is reducible to mere chemistry and physics and information to patterns of energy exchange. In this essay we show that a careful and complete modeling of the transition from pleroma to creatura can clarify what these reductionist assumptions miss and provide an unambiguous connection linking the energetic to the semiotic realm.

A focus on relationships rather than things, distinguishing the material-energetic realm of physics from the informational realm of life and mind. Information is a relationship between things in which one thing is shaped over time by another thing. Any “piece” of information is an irreducible relationship between a sign vehicle, a sign source, and a sign interpreting process. “The difference that makes a difference,” makes that difference to something about something. A piece of information is therefore three things with relationships in their interstices. We, as signal recipients, detect a difference in the sign vehicle. The difference we detect makes a difference to us—it changes us. It makes a difference to us with respect to something that we take the sign vehicle to be about—a sign sender, the difference we make is with regard to the sender.

This is intuitive enough. It becomes counterintuitive when we recognize that so long as we think of sign senders and sign recipients as like us, we are smuggling black boxes into our schema—homunculi who send and interpret messages. To avoid this preformationist assumption, we must recognize, following the philosopher Charles Sanders Peirce, that what inteprets a sign is not merely a locus—some being outside the which itself constitutes a sign vehicle interpreted by yet another sign recipient, and so on. Therefore an informational relationship is not a relationship in isolation. It is part of an information system, a vast network of interrelated relationships.

Many of Bateson’s successors interpreted his last gropings as tipping toward a commitment to subjective idealism, an assumption that minds are independent homunculi, connected to the pleroma only by an article of faith. Others, Cashman and bridge this gap deemed by the idealists to be unbridgeable.

We argue that implicit in Bateson’s distinction between creatura and pleroma is a necessary assumption that creatura emerged somehow from pleroma. To understand the pattern that connects the two realms, then, we must ultimately answer a very specific question: How could creatura get started in an exclusively pleroma universe? Or, to translate into the more familiar biological framework, how could life have emerged here or anyplace in a universe that doesn’t already possess life’s attributes of relationship, function, and evolvabality—a universe governed solely by the known forces of physics and chemistry? Until this question is answered we cannot hope to fully grasp Bateson’s “pattern which connects.”


The problem with protocells

Conventional inquiry into this challenge often employs a reverse engineering approach. Researchers identify the minimal characteristics of life (nucleic acid replication, cell membranes, and so on), and the elements of living systems that embody those characteristics, (DNA, RNA, lipids, and so on). They then imagine scenarios in which by chance alone, these essential constituents of cells might come into proximity and “come alive.” The current experimental work on the origins of life that is considered most promising, involves laboratory efforts to actively construct minimal cell prototypes, as if to provide what engineers would call “proof of concept.”

If the goal were to engineer life, then building a successful prototype would be half the battle. But engineering is precisely what a pre-life universe lacks. Origin of life filling in the un-engineered missing link between physics and biology, but simply trying to put Humpty-Dumpty together again, with a few pieces left out. This may show that life is not some ineffable essence, but does not show how life’s properties can emerge spontaneously from a lifeless world. So in this effort, while recognizing the circularity of arguments from intelligent design, origin of life researchers unwittingly employ reasoning similar to that of intelligent design’s defenders. They act as foresightful watchmakers in their effort to prove that life is the product of a blind watchmaker.
Indeed, the reverse engineering approach to the origins of life parallels watch making. Watchmakers assemble parts that already have been shaped for a specific function. They kick start the resulting product and it becomes animated. Protocell research assembles components of life that have evolved with particular functions. and imagine how nature might bring them together, and then assume that once together, they would come alive.

In two respects, the accretion of life from non-life is more challenging than the reverse engineering approach would suggest. First, the elements to be brought together could not have been previously modified to work together, as are the molecular complexes of cells. They can only be those that can be spontaneously produced in a lifeless context irrespective of one another or any living function. Second, although protocells made of parts salvaged from once-living cells may come to function in an integrated fashion, any such synergy traces to their long evolution not to any spontaneously emergent complementarity. A bricolage constellation of once-living are in this way more like reanimated frankensteinian cells.

The true proof of concept requires demonstrating how critical properties of life could emerge by the spontaneous interactions among inorganically generated molecules. These properties include forming a complex that maintains its individuality despite perturbation and the ability to replicate itself indefinitely if conditions are right. This approach is a far more difficult alternative than reverse engineering from a known end­point, and yet it inevitably involves fewer components in simpler combinations owing to the requirement that it must have arisen spontaneously. To meet this challenge requires vigilance to avoid what could be called the Amnesiac Watchmaker Syndrome—reverse­engineering from life, and then assuming that the engineering effort was irrelevant, as though we found this to be spontaneously produced.

In this paper we offer an exemplar proof-of-concept model that shows how properties of creatura could spontaneously emerge from mere pleroma. We propose a generic model of the transition to life that could apply anywhere in the universe; one that gets a cold start in relentless thermodynamics and molecular coincidence.

By cumulative standards, every step in the transition from non-life to life must be accounted for. Working forward to life instead of backward from life, it becomes obvious that anything approaching the complexity of even the simplest contemporary terrestrial life-forms could not possibly emerge de novo from inorganic chemistry and physics in a single transition. Our emphasis will therefore be on exploring the realm between non-life and life; forms that are not living but nonetheless possess properties that would bias the necessary precursor attributes of anything evolvable.

The challenge for a non-engineering cumulative approach like ours is demonstrating not only how precursor elements might fall together, or even stay together but more importantly how they might become necessary to each other. In the abstract, we might describe this alternative to reverse engineering as searching for the possibility of spontaneous combinatorial synergy, but this is not quite sufficient. The concept of synergy is ambiguous. A weak interpretation of synergy is as a state in which each part is of some benefit to another. A strong interpretation of synergy is as a state in which each part is wholly dependent upon the others. The alternative must be held to the more stringent standard of strong synergy; with components that are both co-dependent and also co-productive.
By this standard, of all of life’s features, the feature that is most central, and that must arise first is the reciprocally productive coupling of component products. As the 18th century philosopher Immanuel Kant argued, “The definition of an organic body is that it is a body, every part of which is there for the sake of the other (reciprocally as end and at the same time means)…An organic body is one in which each part, with its moving force, necessarily relates to the whole (to each part in its composition.)” (Kant, 1790)
In sum then, our goal in what follows is to see pure happenstance produce minimal evolvable products, a population of forms that would be differentially sustained over time depending upon environmental conditions.

Important insights concerning the nature of other emergent transitions as well. Often emergence is treated as a problem for the philosophy of science; one of defining what we mean by sharp inexplicable transitions between the explanatory regimes of physics, chemistry, biology, and consciousness. Emergence occurs when the net effect of the interactions among parts of a system produces a significant shift in the characteristics and behavior of the whole system. If we can provide a complete step-by-step description of one such transition, we should be in a better position to make sense of others—especially as this is a paradigm case. So again, we may be able to improve upon mere descriptive or reverse-engineering analyses of emergent transitions, such as that leading to mind, by comparison to this constructive model. Beyond merely exemplifying emergence, then, we would hope that traversing this one transition, will pave the way to a more subtle and complete understanding of emergent processes in general.

Finally, one further benefit of providing a step-by-step account of the transition from non-life to life is that it can illuminate the concept of purpose or telos, and its origin from a previously purposeless universe. In the debate between science and fundamentalist religion that the world’s citizens watch so attentively, the burden is on science to demonstrate how purposive processes can emerge in the absence of antecedent intelligence, carefully selected prior conditions, or intrinsically teleological components. Until it is possible to show at least in principle how teleological dynamics can emerge de novo, a shadow of doubt will remain about whether mechanistic causality and teleological causality are compatible, and whether consciousness, meaning, and value are ultimately ineffable. Bridging this threshold is the first step toward naturalizing any of the grand mysteries of subjective experience and value, we believe that by tracking the emergence of the fledgling precursor to these intentional relations—function—we will have provided firm evidence that the naturalization of purpose is not an impossibility.

The Thermodynamic Universe

A collection of interacting molecules (for example, a container of water) has no integration of parts, no for-the-whole contribution of one molecule to the rest, but, still, global properties emerge as these interactions produce a kind of vast regression toward the mean. Global features such as surface tension emerge in this way, and they are to some extent independent of many of the details of the molecules involved, since many substances can exhibit this phenomenon. Like the averaging of molecular movements producing temperature, surface tension is not a property of individual molecules or even of a few in interaction; it is a system-wide effect of a very large averaging process. Surface tension is a product of what are called van der Waals’s forces: a weak energetic attraction between like molecules that keeps the space between them at a minimum (a little bit like the stickiness that can hold a statically charged balloon to the wall). The momentum of individual molecules is altered by the presence of nearby molecules in close interaction with each other, causing greater coherence between them than between them and molecules of air which are less tightly coupled.

Emergence in simple thermodynamic systems flows from the logic of the second law of thermodynamics, which, although based on the billiard ball-like interactions of statistical. It is a rule about probable and improbable patterns and how they are likely to follow each other in time. Although this rule is not so specific or absolute as are Newtonian laws of motion, it is all but guaranteed, in the same way that shuffling a deck of cards hundreds of thousands of times is still hugely unlikely to ever result in an arrangement in which each of the suits is separated and numerically ordered. The organizing effect exemplified by system properties such as surface tension occurs because the statistics of the ramifying and recirculating exchanges of energy eventually pits every difference of movement against every other, eventually leading toward thorough mutual cancellation, and thus uniformity. So, before life and before purpose, we can apply the concept of emergence in a minimal sense to these highly robust system­level tendencies. It is important to note, however, that these are the product not of new forces, but, rather, of population effects of the same forces. And, yet, the system-level tendencies have a new kind of causal efficacy that while based on the system’s individual elements is primarily the result of the distributional characteristics of their repeated interactions. This why both water and alcohol can behave in ways that are almost indistinguishable.