Leon Chwistek (b. January 13, 1884 in Kraków, Poland - August 20, 1944 near Moscow, Russia) was a Polish Avant-garde painter, theoretician of modern art, literary critic, logician, philosopher and mathematician.

In the 1920s-30s many philosophers in Europe attempted to reform traditional philosophy by means of mathematical logic. Leon Chwistek did not believe that such a reform could succeed. He thought that reality could not be described in one homogenous system, which would be based on the principles of formal logic, because there is not one reality but many.

Chwistek developed his theory of the multiplicity of realities first with regard to the arts. He distinguished four basic types of realities and then matched them with four basic types of painting.

Here are the four types of realities:

1. The popular reality (common-sense realism)

2. The physical reality (constructed by physics)

3. The phenomenal reality (sensual impressions)

4. The visionary/intuitive reality (dreams, hallucinations, subconscious states).

The types of painting which correspond to the above are:

1. Primitivism

2. Realism

3. Impressionism

4. Futurism

Chwistek never intended his views to constitute a new metaphysical theory. He was a defender of "sound reason", against metaphysics and the irrationalistic feelings. His theory of plural reality was merely an attempt to specify the various ways in which the term “real” is used. It is interesting that Witkiewicz, although Chwistek’s closest friend, harshly criticized his friend’s philosophical views.

Wikiewicz’s philosophy was based on the idea of monadic character of the existence of the individual, which embraces multiplicity of existences, and the world being made up of a multiplicity of Particular Existences.