This classic work by Gregory Bateson deserves to be read by anyone seriously interested in cognitive science, artificial intelligence, evolutionary biology, epistemology, philosophy (in particular, logic), or any related field. Bateson illustrates in brilliant fashion a number of key concepts which "every schoolboy should know", but which, unfortunately, have escaped the notice of a wide variety of philosophers and scientists---if not every schoolboy, certainly every professional scientist and philosopher should be familiar with this work, whether they agree with it or not.
The basic ideas behind his work are subtle, yet Bateson does an excellent job of describing them clearly. In the process he manages to present and lucidly explain a wonderful solution to the mind-body problem which requires no supernatural forces, yet accounts very clearly for our intuitive perception that mind is in some sense non-physical. His information-theoretic approach is profound yet simple. His ideas touch upon many very deep issues, ranging from the definition of mental process itself to the logical distinctions between different levels of logical type, and also clearly illustrates and explains the origin of some of the major problems in formal logic, including why self-referential paradoxes arise in formal logical systems, and what this says about the limitations of these systems (and how one can get around these problems!). The work touches on many different aspects of many seemingly unrelated fields, and ties them together with a set of powerful and yet graspable abstractions which allow you to re-frame with clarity some of the greatest philosophical problems mankind has faced. It is a wonderful, poetic, and yet starkly rational approach which deserves to be read by every serious student of modern thought.
Bateson's work here, interesting and thought-provoking as it is, is nevertheless unfinished---much more needs to be done to further extend his ideas---some obvious ways in which his work could be taken further include exploring its relationship to dynamical systems theory and chaos theory, fractal mathematics, and other more abstract philosophical areas.
This book is an excellent introduction to Bateson's work and thought, and should be required reading for many college courses in different departments. Unfortunately, it is currently out of print, which is a terrible shame.