In this appendix I shall examine Bateson’s six criteria of mental process and compare them to the Santiago theory of cognition. 1
1. A mind is an aggregate of interacting parts or components.
This criterion is implicit in the concept of an autopoietic network, which is a network of interacting components.
2. The interaction between parts of mind is triggered by difference.
According to the Santiago theory, a living organism brings forth a world by making distinctions. Cognition results from a pattern of distinctions, and distinctions are perceptions of difference. For example, a bacterium, as mentioned on page 268, perceives differences in chemical concentration and temperature.
Thus both Maturana and Bateson emphasize difference, but whereas for Maturana the particular characteristics of a difference are part of the world that is brought forth in the process of cognition, Bateson, as Dell points out, treats differences as objective features of the world. This is apparent in the way Bateson introduces his notion of difference in Mind and Nature:
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All receipt of information is necessarily the receipt of news of difference, and all perception of difference is limited by threshold. Differences that are too slight or too slowly presented are not perceivable. 2
In Bateson’s view, then, differences are objective features of the world, but not all differences are perceivable. He calls those that are not perceived “potential differences” and those that are “effective differences.” The effective differences, Bateson explains, become items of information, and he offers this definition: “Information consists of differences that make a difference.” 3
With this definition of information as effective differences, Bateson comes very close to Maturana’s notion that perturbations from the environment trigger structural changes in a living organism. Bateson also emphasizes that different organisms perceive different kinds of differences and that there is no objective information or objective knowledge. However, he holds on to the view that objectivity exists “out there” in the physical world, even though we cannot know it. The idea of differences as objective features of the world becomes more explicit in Bateson’s last two criteria of mental process.
3. Mental process requires collateral energy.
With this criterion Bateson emphasizes the distinction between the ways living and nonliving systems interact with their environments. Like Maturana, he clearly distinguishes between the reaction of a material object and the response of a living organism. But whereas Maturana describes the autonomy of the organism’s response in terms of structural coupling and nonlinear patterns of organization, Bateson characterizes it in terms of energy. “When I kick a stone,” he argues, “I give energy to the stone, and it moves with that energy. . . . When I kick a dog, it responds with energy [it received] from [its] metabolism.” 4
However, Bateson was well aware that nonlinear patterns of organization are a principal characteristic of living systems, as his next criterion shows.
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4. Mental process requires circular {or more complexj chains of determination.
The characterization of living systems in terms of nonlinear patterns of causality was the key that led Maturana to the concept of autopoiesis, and nonlinear causality is also a key ingredient in Prigogine’s theory of dissipative structures.
Bateson s first four criteria of mental process, then, are all implicit in the Santiago theory of cognition. In his last two criteria, however, the crucial difference between Bateson’s and Maturana’s views of cognition becomes apparent.
5. In mental process, the effects of difference are to be regarded as transforms (that is, coded versions) of events that preceded them.
Here Bateson explicitly assumes the existence of an independent world, consisting of objective features such as objects, events, and differences. This independently existing outer reality is then transformed,” or “encoded,” into an inner reality. In other words, Bateson adheres to the idea that cognition involves mental representations of an objective world.
Bateson s last criterion elaborates the “representationist” position further.
6. The description and classification of these processes of transformation disclose a hierarchy of logical types immanent in the phenomena.
To explain this criterion Bateson uses the example of two organisms communicating with each other. Following the computational model of cognition, he describes communication in terms of messages—that is, objective physical signals, such as sounds—that are sent from one organism to the other and then encoded (that is, transformed into mental representations).
In such communications, Bateson argues, the exchanged information will consist not only of messages, but also of messages about coding, which constitute a different class of information. They are messages about messages, or “meta-messages,” which Bateson characterizes as being of a different “logical type,” borrowing this term from the philosophers Bertrand Russell and Al-
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fred North Whitehead. This proposition then naturally leads Bateson to postulate “messages about meta-messages,” and so on—in other words, a “hierarchy of logical types.” The existence of such a hierarchy of logical types is Bateson’s last criterion of mental process.
The Santiago theory, too, provides a description of communication among living organisms, fn Maturana’s view communication does not involve any exchange of messages or information, but it does include “communication about communication” and thus what Bateson calls a hierarchy of logical types. However, according to Maturana, such a hierarchy emerges with human language and self-awareness and is not characteristic of the general phenomenon of cognition. 5 With human language arise abstract thinking, concepts, symbols, mental representations, self-awareness, and all the other qualities of consciousness. In Maturana’s view Bateson’s codes, “transforms,” and logical types—his last two criteria—are characteristics not of cognition in general, but of human consciousness.
During the last years of his life Bateson struggled to find additional criteria that would apply to consciousness. Although he suspected that “the phenomenon is somehow related to the business of logical types,” 6 he failed to recognize his last two criteria as criteria of consciousness, rather than mental process. I believe that this error may have prevented Bateson from gaining further insights into the nature of the human mind.