This is a treatise on epistemology which is at once an argument against traditional ""muddleheaded"" thinking (mind/body dualism) and a thesis that biological evolution and creative thought are similar processes. Both have a double structure, Bateson says, and much of the text is an elaboration of the parallel characteristics of mind and nature. This is heady stuff and the early introduction of numerous references to ""see glossary"" for ""stochastic,"" ""typology,"" etc., will not sustain the faint of heart. Indeed, readers not familiar with Bertrand Russell's solution to logical paradoxes through the hierarchy of types may fail by the wayside. Courage. Further on, anthropologist Bateson describes his early work in New Guinea which provides a context for his style of thinking. In analyzing the Iakmul culture, he found the study of interactive processes to be fundamental. In particular, he discerned two general types of interaction: symmetric, e.g., aggression/aggression, boasting/boasting; or complementary, e.g., dominance/submission, nurture/dependency. The two contrasting types of interaction had a self-corrective tendency so that a runaway situation of dominance leading to more dominance could be defused by the addition of competitiveness. This kind of reasoning allows Bateson to arrive at basic criteria of mind: 1. A mind is an aggregate of interacting parts. . . 2. The interactions of parts of mind are triggered by difference. . . and so on. Many of Bateson's ideas are stimulating, if at times obscure or somewhat limiting. What has been left out? Bateson himself affirms he has not yet coped with consciousness or aesthetics. Presumably a grander synthesis will come in a future volume, where, it is to be hoped, the presentation will flow in a more orderly way, reflecting selectivity even within randomness.