Popper's three worlds

Popper's three worlds is a way of looking at reality, described by the British philosopher Karl Popper in a lecture given in August 1967.^[1] The concept involves three interacting worlds, called world 1, world 2 and world 3.^[2]

Worlds 1, 2 and 3

Popper split the world into three categories:

World 1: the world of physical objects and events, including biological entities
World 2: the world of individual mental processes
World 3: the world of abstractions that emerge from and have an effect back on world 2 through their representations in world 1.^[3]

More on world 3

Popper's world 3 contains the products of thought. This includes abstract objects such as scientific theories, stories, myths and works of art.^[4] A world 3 object is something along the lines of a meta-object or a form of being. But, world 3 is not to be conceived as a Platonic realm, because unlike the Platonic world of forms, which is non changing and exists independently of human beings, Popper's world 3 is created by human beings and is not fixed.^[5] It corresponds to the current state of our knowledge and culture.^[6]

The interaction of world 1 and world 2

The theory of interaction between world 1 and world 2 is an alternative theory to Cartesian dualism, which is based on the theory that the universe is composed of two essential substances: res cogitans and res extensa. Popperian cosmology rejects this essentialism, but maintains the common sense view that physical and mental states exist, and they interact.

The interaction of world 2 and world 3

The interaction of world 2 and world 3 is based on the theory that world 3 is partially autonomous. For example, the development of scientific theories in world 3 leads to unintended consequences, in that problems and contradictions are discovered by world 2. Another example is that the process of learning causes world 3 to change world 2.

The interaction of world 3 and world 1

The world 3 objects are embodied in world 1. For example, the intrinsic value of Hamlet as a world 3 object is embodied many times in world 1. But, this representation of an object of world 3 into an object of world 1 is not considered an interaction in Popper's view. Instead, for Popper, because world 3 is a world of abstractions, it can only interact with world 1 through world 2.^[7]^[8]

Notes and abbreviated references

^ Popper 1968.
^ Eccles 1970, p. 163–169.
^ Eccles 1970, p. 165: "In their material composition of paper and ink, books are in world 1, but the codified knowledge conveyed in the print is in world 3."
^ Heller 2011, p. 118–120.
^ Niiniluoto 2006, p. 61: "The most important difference between Platonism and Popper is the fact that world 3 is created by human beings."
^ Eccles 1970, p. 165: "Most important components of world 3 are the theoretical systems comprising scientific problems and the critical arguments generated by discussions of these problems."
^ Eccles 1970, p. 165: "Popper specifies for these three worlds, namely that there is reciprocal transmission between 1 and 2 and between 2 and 3, but that 1 and 3 can interact only by mediation of World 2."
^ Popper 1972, p. 155: "The first world and the third world cannot interact, save through the intervention of the second world, the world of subjective or personal experiences."

References

Eccles, J. C. (1970). Facing Reality: Philosophical Adventures by a Brain Scientist. Springer Science & Business Media. ISBN 978-1-4757-3997-8.
Heller, Michael (2011). Philosophy in Science: An Historical Introduction. Springer.
Niiniluoto, Ilkka (2006). "World 3: A Critical Defence". In Jarvie, Ian; Milford, Karl; Miller, David (eds.). Karl Popper: Metaphysics and epistemology. Ashgate.
Popper, Karl (1968) [reprinted in Popper 1972, chap. 3.]. Epistemology Without a Knowing Subject. Third International Congress for Logic, Methodology and Philosophy of Science, 25 August 1967. Amsterdam.
Popper, Karl (1972). Objective Knowledge: An Evolutionary Approach.