In 1965, Joseph Kosuth moved from Ohio to New York, where he began creating experimental conceptual installations, museum exhibitions, and public commissions that explore the role of language and meaning within art. Kosuth's practice is highly self-referential, drawing influence from Sigmund Freud and Ludwig Wittgenstein's seminal theories. "The 'value' of particular artists after Duchamp can be weighed according to how much they questioned the nature of art," Kosuth has said. One of his best known works is One and Three Chairs (1965), a visual expression of Plato’s Theory of Forms. In the collection at the Museum of Modern Art, the piece features a wooden chair, a photograph of the chair, and a dictionary definition of the word “chair.” Plato’s theory asserts that non-material abstract forms (or ideas), and not the physical world, possess the highest and most fundamental kind of reality.