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 in 1978. The concept involves three interacting worlds, called World 1, World 2 and World 3.

Worlds 1, 2 and 3

Popper split the world into three categories:
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.

World 3

Popper's World 3 contains the products of thought. This includes abstract objects such as scientific theories, stories, myths, tools, social institutions, and works of art. World 3 is not to be conceived as a Platonic realm, because it is created by humans.

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 1 and World 3

Other entities are contained in World 3, such as feats of engineering and art. The World 3 objects, although they exist in World 1, are embodied and given extra meaning by World 3. For example, the intrinsic value of Hamlet as a World 3 object is embodied many times in World 1, the physical world. This idea would be something along the lines of a meta-object, or a form of being.

The interaction of World 1, World 2 and World 3

As a pluralist, laid out in his Tanner Lecture, Popper views interactions between all three worlds as a matter of course. This is similar to the linkages made by William Kirk between the 'phenomenal environment' of physical facts and social facts and decisions made in the 'behavioural environment'. A discussion between Popper's three worlds and Kirk's views has been made by Bird who also discusses the three worlds in relation to methodological implications for geography.