This is a confusing and difficult book. It feels like it was left unfinished,
with ideas barely sketched.
The goal was to provide a unified view of cognitive and biological phenomena, built around a fundamental assumption: that the substance of the biological world is "pattern".
The book opens with a discussion that Nature prefers double/dual systems: two sources of information are infinitely better than one. Hence two eyes and not just one. One eyes would see only in two dimensions. Two eyes reveal a third dimension, depth. Hence two sexes and not just one. Information is the difference that results from the comparison of two things, and it is more than the sum of the parts.
The book's big thesis is that life is due to dual stochastic processes, each stochastic system driven by a random process and checked by a nonrandom process. One stochastic system is the genetic one, and here it is fairly clear what Bateson is referring to. The other one, though, is confusingly called "learning" and sometimes "somatic change" (which means body changes). Genetic change is a stochastic process that is triggered by randomness. Bateson thinks the same of "learning" (somatic change? development of the individual body? epigenesis?): also a stochastic process triggered by randomness. Both random processes are "selected" by a nonrandom process, whether the need to preserve the organism's internal organization or the need to adapt to the environment. Without the randomness it would be impossible to create something new, there would only be conservation of the old (the nonrandom system). In both of these stochastic processes a large number of alternatives is generated and then the nonrandom selection process prunes that set of alternatives. The obvious difference between the two is that learning happens during a lifetime, whereas evolution happens over the course of many generations. The other difference is that genetic change has a direct impact on somatic change, whereas somatic change merely creates the conditions for genetic change. The combination of the two stochastic processes works in a manner similar to a cybernetic system: a feedback process controls what is actually possible.
Bateson then shows that thought too is due to dual stochastic processes. Creative thought relies on some initial randomness which is then assimilated into a preexisting system of beliefs according to a requirement of coherence or rigor (which is a nonrandom process). At the same time thought generates many alternatives that are selected by a nonrandom process of reinforcement.
Even more confusing is his division of each process into a digital component and an analogic component. He claims that the source of randomness in one stochastic system is digital (the DNA) and in the other one is analogic (the body and the environment). Then he tries to find a similar duality in thought processes: he views the brain as a digital system (the source of random ideas) and the interaction with the world would be an analogic source of randomness (never explained, only hinted at). On one hand there are creative ideas and on the other hand there is formation of habits.
Reading the book also requires familiarity with Bertrand Russell's theory of logical types.
TM, ®, Copyright © 2012 Piero Scaruffi