mind and nature

is an excellent book by Gregory Bateson (isbn 1-57273-434-5). As usual I'm going to quote from a few pages:

If you want to understand mental processes, look at biological evolution and conversely if you want to understand biological evolution, go look at mental processes.

How is the world of logic, which eschews "circular argument," related to a world in which circular trains of causation are the rule rather than the exception?

Perception operates only on difference. All receipt of information is necessarily the receipt of news of difference, and all perception is necessarily limited by threshold. Differences that are too slight or too slowly presented are not perceivable.

The universe is characterized by an uneven distribution of causal and other types of linkage between its parts; that is, there are regions of dense linkage separated from each other by regions of less dense linkage.

We should define "stability" always by reference to the ongoing truth of some descriptive proposition.

Notoriously it is very difficult to detect gradual change because along with our high sensitivity to rapid change goes also the phenomenon of accommodation. Organisms become habituated. To distinguish between slow change and the (imperceptible) unchanging, we require information of a different sort; we need a clock.

Stability may be acheived either by rigidity or by continual repetition of some cycle of smaller changes, which cycle will return to a status quo ante after every disturbance.

Every given system embodies relations to time, that is, was characterized by time constants determined by the given whole. These constants were not determined by the equations of relationship between successive parts but were emergent properties of the system.

The shape of what it deposits is determined by the shape of the previous growth.

What characterizes those adaptations that turn out to be disasterous, and how do these differ from those that seem to be benign and, like the crab's claw, remain benign through geological ages?

Above all, in sexual reproduction, the matching up of chromosomes in fertilization enforces a process of comparison. What is new in either ovum or spermatozoon must meet with what is old in the other, and the test will favour conformity and conservation. The more grossly new will be eliminated on grounds of incompatibility.

It is very easy to fall into the notion that if the new is viable, then there must have been something wrong with the old. This view, to which organisms already suffering the pathologies of over rapid, frantic social change are inevitably prone, is, of course, mostly nonsense. What is always important is to be sure that the new is not worse than the old.