Is Terrence Deacon's Metaphysics of Incompleteness Still Incomplete?

I. Introduction

Terrence Deacon, author of Incomplete Nature: How Mind Emerged from Matter, proposes that constraint understood as constitutive absence is a necessary factor in the emergence of life from nonlife, mind from matter. By "constraint" he means "the property of being restricted or being less variable than possible."¹ By "absence" he means that constraint is a negative property qualifying a collection or ensemble of constituent parts or members: "It is a way of referring to what is not exhibited, but could have been, at least under some circumstances" (193). By "constitutive absence" he means what is the case "irrespective of whether this is registered by any act of observation" (192). So constraint thus understood is metaphysically grounded in something constitutive of the way nature works. This kind of constraint is not externally imposed by some outside agency but internally by reason of "the dynamical organization of a somewhat diverse class of phenomena which share in common the tendency to become spontaneously more organized and orderly over time due to constant perturbation" (237). Deacon cautions that these processes of internal organization have been called "self-organizing," but that in fact there is no self to do the organizing of their inanimate components (e.g., molecules) (237-38). Instead, what is thought to be self-organizing is in fact due to persistent coincidences in nature's mode of operation ("micro-configurational particularities") that become over time habitual patterns ("macro-configurational regularities"). These habitual patterns together constitute the corporate reality of a physical system with internally generated constraints on its normal mode of operation. "This centrality of form-begetting form is what justifies calling these processes morphodynamic" (261).

I applaud Deacon for his willingness to move beyond scientific description to account for the way in which higher-order systems emerge out of the dynamic interplay of lower-order systems within physical reality. His resulting metaphysics of evolution is clearly different from the substance-accident metaphysics of Aristotle in which the substantial form of an individual entity governs from the top-down the material constituents of that same entity. For, as Deacon makes clear in Incomplete Nature, "being alive does not merely consist in being composed in a particular way. It consists in changing in a particular way" (175). An Aristotelian substantial form is basically fixed in its mode of operation. It is thus ill suited to be the governing principle in an evolving life-system in which the mode of operation of the system keeps evolving in the direction of greater order and complexity. But is it enough to claim that the "constitutive absence" of a substantial form to govern its mode of operation suffices to explain from a philosophical perspective how the life-system continues to evolve in an orderly manner? Deacon's appeal to the notion of mutual constraint as the way that the components of a given system dynamically interrelate is simply a description of what happens, not of why it happens.

The deeper philosophical explanation of ongoing change within a life-system would seem to lie in the capacity or potentiality of the components of the system to interact with one another in an orderly rather than a chaotic and disorganized manner. But the capacity for that kind of change is not present in inanimate constituents—only in components that are alive and thus capable of significantly altering their relationship to one another. As we shall see below, Deacon avoids this implication because in his mind it ends up in an affirmation of pan-psychism ("mind all the way down"). But can he then consistently explain how life is unexpectedly emergent from nonlife and how human self-consciousness can be emergent from animal sentience? Can the self-organizing character of a morphodynamic system, for example, be accounted for simply by reference to "coincidences" and "habitual patterns" in the objective workings of nature?

In this article, I first set forth in some detail Deacon's argument in Incomplete Nature that increasing levels of objective constraint in hierarchically ordered systems of inanimate constituents suffice to account for the emergence of life from nonlife and consciousness...