---
title: "Incomplete Nature"
chunk: 1/4
source: "https://en.wikipedia.org/wiki/Incomplete_Nature"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:32:47.944742+00:00"
instance: "kb-cron"
---

Incomplete Nature: How Mind Emerged from Matter is a 2011 book by biological anthropologist Terrence Deacon. The book covers topics in biosemiotics, philosophy of mind, and the origins of life. Broadly, the book seeks to naturalistically explain "aboutness", that is, concepts like intentionality, meaning, normativity, purpose, and function; which Deacon groups together and labels as ententional phenomena.

== Core ideas ==
Deacon's first book, The Symbolic Species focused on the evolution of human language. In that book, Deacon notes that much of the mystery surrounding language origins comes from a profound confusion about the nature of semiotic processes themselves. Accordingly, the focus of Incomplete Nature shifts from human origins to the origin of life and semiosis. Incomplete Nature can be viewed as a sizable contribution to the growing body of work positing that the problem of consciousness and the problem of the origin of life are inexorably linked. Deacon tackles these two linked problems by going back to basics. The book expands upon the classical conceptions of work and information  in order to give an account of ententionality that is consistent with materialism and yet does not seek to explain away or pass off as epiphenominal the non-physical properties of life.

== Constraints ==
A central thesis of the book is that absence can still be efficacious. Deacon makes the claim that just as the concept of zero revolutionized mathematics, thinking about life, mind, and other ententional phenomena in terms of constraints (i.e., what is absent) can similarly help us overcome the artificial dichotomy of the mind body problem. A good example of this concept is the hole that defines the hub of a wagon wheel. The hole itself is not a physical thing, but rather a source of constraint that helps to restrict the conformational possibilities of the wheel's components, such that, on a global scale, the property of rolling emerges.  Constraints which produce emergent phenomena may not be a process which can be understood by looking at the make-up of the constituents of a pattern. Emergent phenomena are difficult to study because their complexity does not necessarily decompose into parts. When a pattern is broken down, the constraints are no longer at work; there is no hole, no absence to notice. Imagine a hub, a hole for an axle, produced only when the wheel is rolling, thus breaking the wheel may not show you how the hub emerges.

== Orthograde and contragrade ==
Deacon notes that the apparent patterns of causality exhibited by living systems seem to be in some ways the inverse of the causal patterns of non-living systems. In an attempt to find a solution to the philosophical problems associated with teleological explanations, Deacon returns to Aristotle's four causes and attempts to modernize them with thermodynamic concepts.

Orthograde changes are caused internally. They are spontaneous changes. That is, orthograde changes are generated by the spontaneous elimination of asymmetries in a thermodynamic system in disequilibrium. Because orthograde changes are driven by the internal geometry of a changing system, orthograde causes can be seen as analogous to Aristotle's formal cause. More loosely, Aristotle's final cause can also be considered orthograde, because goal oriented actions are caused from within.
Contragrade changes are imposed from the outside. They are non-spontaneous changes. Contragrade change is induced when one thermodynamic system interacts with the orthograde changes of another thermodynamic system. The interaction drives the first system into a higher energy, more asymmetrical state. Contragrade changes do work. Because contragrade changes are driven by external interactions with another changing system, contragrade causes can be seen as analogous to Aristotle's efficient cause.

== Homeodynamics, morphodynamics, and teleodynamics ==
Much of the book is devoted to expanding upon the ideas of classical thermodynamics, with an extended discussion about how consistently far from equilibrium systems can interact and combine to produce novel emergent properties. 

Deacon defines three hierarchically nested levels of thermodynamic systems: Homeodynamic systems combine to produce morphodynamic systems which combine to produce teleodynamic systems. Teleodynamic systems can be further combined to produce higher orders of self organization.

=== Homeodynamics ===
Homeodynamic systems are essentially equivalent to classical thermodynamic systems like a gas under pressure or solute in solution, but the term serves to emphasize that homeodynamics is an abstract process that can be realized in forms beyond the scope of classic thermodynamics. For example, the diffuse brain activity normally associated with emotional states can be considered to be a homeodynamic system because there is a general state of equilibrium which its components (neural activity) distribute towards. In general, a homeodynamic system is any collection of components that will spontaneously eliminate constraints by rearranging the parts until a maximum entropy state (disorderliness) is achieved.

=== Morphodynamics ===
A morphodynamic system consists of a coupling of two homeodynamic systems such that the constraint dissipation of each complements the other, producing macroscopic order out of microscopic interactions. Morphodynamic systems require constant perturbation to maintain their structure, so they are relatively rare in nature. The paradigm example of a morphodynamic system is a Rayleigh–Bénard cell. Other common examples are snowflake formation, whirlpools and the stimulated emission of laser light.