6 ideas
When a person receives contradictory messages at different logical levels, cannot escape the relationship, and cannot comment on the contradiction, they are placed in an unwinnable position. Repeated exposure to this structure — not a single trauma — can produce schizophrenic patterns of response as the only coherent adaptation to an incoherent demand.
Information is not a thing or substance but a difference that produces an effect somewhere downstream. The unit of mind is the transform of a difference traveling through a circuit, meaning meaning resides in relationships and distinctions, not in objects themselves.
Learning occurs at hierarchical levels: Learning I is acquiring a specific response, Learning II is learning the context or pattern of how to learn (deutero-learning), and Learning III is changing the system of contexts itself. Confusing or mismatching these levels — treating a higher-order frame as if it were a first-order fact — generates paradox and pathology.
Mind is not contained in the skull but distributed across the circuit of organism-plus-environment, wherever differences travel and feed back. The boundary of the thinking system is wherever the relevant information loops close, so a blind man's stick or a forest can be part of the mental system.
Conscious purpose selectively perceives only the short arcs of cause-and-effect relevant to its immediate goals, blinding it to the larger circular structures that sustain the system. This partial vision lets purposeful intervention destroy the very balances it depends on, which is why goal-driven action against ecosystems and bodies produces self-defeating consequences.
At a marine park in Hawaii (Sea Life Park), trainers rewarded a rough-toothed porpoise only for behaviour she had never shown before, so each session's rewarded trick went unrewarded in the next. After many sessions of apparent frustration, she burst into a display of several entirely new behaviours, showing she had learned the rule of the context, 'produce something novel', rather than any single trick. Bateson used the episode as concrete evidence that animals can learn about the context of learning itself, and that the frustration of repeated wrong-context errors can be stressful enough to disrupt the relationship with the trainer.