Among the inmates of my ‘third world’ [World 3] are, more especially, theoretical systems; but inmates just as important are problems and problem situations. And I will argue that the most important inmates of this world are critical arguments, and what may be called—in analogy to a physical state or to a state of consciousness—the state of a discussion or the state of a critical argument; and, of course, the contents of journals, books and libraries. …
Let me repeat one of my standard arguments for the (more or less) independent existence of the third world [World 3].
I consider two thought experiments:
Experiment (1). All our machines and tools are destroyed, and all our subjective learning, including our subjective knowledge of machines and tools, and how to use them. But libraries and our capacity to learn from them survive. Clearly, after much suffering, our world may get going again.
Experiment (2). As before, machines and tools are destroyed, and our subjective learning, including our subjective knowledge of machines and tools, and how to use them. But this time, all libraries are destroyed also, so that our capacity to learn from books becomes useless.
If you think about these two experiments, the reality, significance, and degree of autonomy of the third world [World 3] (as well as its effects on the second and first worlds [Worlds 2 and 1]) may perhaps become a little clearer to you. For in the second case, there will be no re-emergence of our civilization for many millenia. [107-8]