“Monistic theories (monism) defend a single type of substance that composes reality (for example, matter -materialism-. Others instead claim that the spirit or psyche -panpsychism-).
Dualistic theories (dualism) defend two types of substances (for example, body and mind) or two worlds (earth and sky).
Trialist theories (trialism) defend the existence of three types of substances or three types of realities. The graphic presented here resonates with the doctrine of the three worlds of Karl Popper. In it, Popper divides the world into three categories:
- World 1: Physical. The world of objects, not only visible, also things that escape the human eye. It is the world of physical objects.
- World 2: Experience / Feeling. The world of mental processes, conscious or unconscious. It is the place where feelings of pain, pleasure and thought occur. It is the world of subjective experiences.
- World 3: Ideas / Knowledge. It is the world where objective knowledge is found.
In his book “In search of a better world”, in the first of his articles (“Knowledge and configuration of reality”), Popper speaks of three worlds. World 1, the material; world 2, that of experience, and world 3, that of the products of the human mind; and indicates that it seems clear that world 1 is the creator of world 2.
In a way trialism could be considered a level of complexity sufficient to represent all theories, but from other approaches, it may not be enough, and we have to go to a quadrialism (adding identity as a fourth element) and even go further. A complete simulation environment must support monism, dualism, trialism, quadrialism, etc.”
Source: What are the different types of elements that constitute reality in its most essential aspect?