From The Encyclopedia of Comparative Psychology, G. Greenberg and M. Haraway (Eds.), New York: Garland Publishers, Inc. 1997


 Thermodynamics, Evolution, and Behavior

Rod Swenson
Center for the Ecological Study of Perception and Action
University of Connecticut
It was Descartes' dualistic world view that provided the metaphysical foundation for the subsequent success of Newtonian mechanics and the rise of modern science in the seventeenth century, and it was here at their modern origins as part of this dualistic world view that psychology and physics were defined by their mutual exclusivity. According to Descartes, the world was divided into the active, striving, end-directed psychological part (the perceiving mind, thinking I, or Cartesian self) on the one hand, and the "dead" physical part on the other. The physical part of the world (matter, body), defined exhaustively by its extension in space and time, was seen to consist of reversible (without any inherent direction to time), qualityless particles governed by rigidly deterministic law from which the striving, immaterial mind, without spatial or temporal dimension, was immune.
xxArguing that the active, end-directed striving of living things in general (Descartes had limited the active part of the world to human minds) could not be adequately described or accounted for as part of a dead, reversible, mechanical world, Kant promoted a second major dualism, the dualism between physics and biology, or between the active striving of living things and their dead physical environments. The Cartesian-Kantian dualistic tradition was built into evolutionary theory with the ascendancy of Darwinism where physics was given no role to play and "organisms and environments were totally separated" (Lewontin, 1992, p. 108). The same Kantian argument for the "autonomy of biology" from physics based on the apparent incommensurability of physics with the active, end-directedness of living things has been used by leading proponents of Darwinism right up to recent times (e.g., Mayer, 1985).
xxIn this century, Boltzmann's view of the second law of thermodynamics as a law of disorder (advanced during the last quarter of the nineteenth century) became the apparent physical basis for justifying the postulates of incommensurability (the first between psychology and physics, and the second between biology and physics). With the physics of Newton the world consisted of passive particles that had to be ordered, but with Boltzmann's view the physical world was not just assumed to be "dead" or passive, but constantly working to do destroy order. Given this view, it is "no surprise," in the words of Levins and Lewontin (1985, p. 19) "that evolutionists [came to] believe organic evolution to be the negation of physical evolution." As Ronald Fisher (1930/1958, p. 39), one of the founders of neo-Darwinism, wrote about the apparent incommensurability between living things and their environments, between biology and physics, or, more particularly, between evolution and thermodynamics, "entropy changes lead to a progressive disorganization of the physical world...while evolutionary changes [produce] progressively higher organization...".
xxContrary to many of his contemporaries who simply accepted the postulates of incommensurability as given, Fisher wondered out loud about the unification of the two opposite directions apparently taken by evolution and thermodynamics under a deeper more general principle. Although this did not happen in Fisher's lifetime, now, at the end of this century we can perform such a unification. It can now be shown that the active, end-directed, or intentional dynamics of living things, their reciprocal relation to their environments, and evolution as a general process of dynamically ordered things that actively work to bring more order into the world is the production of an active order-producing world following directly