Leon Chwistek (Kraków, Austria-Hungary, 13 June 1884 – 20 August 1944, Barwicha near Moscow, Russia) was a Polish avant-garde painter, theoretician of modern art, literary critic, logician, philosopher and mathematician.

Logic and philosophy

Starting in 1929 Chwistek was a Professor of Logic at the University of Lwów in a position for which Alfred Tarski had also applied. His interests in the 1930s were in a general system of philosophy of science, which was published in a book translated in English 1948 as The Limits of Science.

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

Chwistek demolishes the axiomatic method by demonstrating that the extant axiomatic systems are inconsistent.

Artist

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

The four types of realities were:

• 1. popular reality (common-sense realism)
• 2. physical reality (constructed by physics)
• 3. phenomenal reality (sensory impressions)
• 4. visionary/intuitive reality (dreams, hallucinations, subconscious states).

The types of painting corresponding to the above were:

• 1. Primitivism
• 2. Realism
• 3. Impressionism
• 4. Futurism

Chwistek never intended his views to constitute a new metaphysical theory. He was a defender of "common sense" against metaphysics and irrational feeling. His theory of plural reality was merely an attempt to specify the various ways in which the term, “real,” is used.

Chwistek's fellow-artist and closest friend, Stanislaw Ignacy Witkiewicz, harshly criticized his philosophical views. Witkiewicz’s own philosophy was based on a monadic character to the individual's existence, embracing a multiplicity of existences, with the world being made up of a multiplicity of Particular Existences.