Laws of Form
George Spencer-Brown wrote a seminal book called the Laws of Form (LoF) (George Spencer-Brown, 17 april 1969). It is a work of mathematics with a philosophical inclination at its most fundamental level, but it is written in such an inconvenient way that it is difficult to grasp, even for schooled mathematicians. It takes several rereadings to get acquainted with the fundamental ideas being explored, but it is certainly worth the effort. Some people regard reading LoF as a life changing experience.
So, what is LoF all about? This question is best answered by Spencer-Brown himself.
The theme of this book is that a universe comes into being when a space is severed or taken apart. The skin of a living organism cuts off an inside from an outside. So does the circumference of a circle in a plane. By tracing the way we represent such a severance, we can begin to reconstruct, with an accuracy and coverage that appear almost uncanny, the basic forms underlying linguistic, mathematical, physical, and biological science, and can begin to see how the familiar laws of our own experience follow inexorably from the original act of severance. The act is itself already remembered, even if unconsciously, as our first attempt to distinguish different things in a world where, in the first place, the boundaries can be drawn anywhere we please.
Obviously, this quote demands an explanation. An explanation is given in such a way that a direct connection with the social theory of a sustainable, collaborative learning society can be made.