Tertium Organum

Ouspensky claims that his book represents the "third organ of knowledge", after Aristotle's logic and Bacon's empirical method, and proposes a new way of knowing that transcends the limitations of three-dimensional thinking.

The book explores the nature of consciousness, space and time, arguing that our perception of reality is limited by the three-dimensional mind. Ouspensky introduces the concept of a fourth dimension, which he associates with time and higher consciousness. He believes that humans can reach a higher state of consciousness through inner development, which allows them to understand the world beyond physical limitations. Inspired by mathematical ideas and Eastern philosophy, he suggests that the fourth dimension is the key to the realization of absolute truth.

Ouspensky also examines the relationship between subject and object, arguing that reality is subjective and that consciousness is the basis of all that exists. He criticizes materialism and calls for a holistic approach that combines science and spirituality. The book has had a strong influence on esoteric and philosophical circles, especially through its association with the teachings of G. I. Gurdjieff, and remains significant for the study of metaphysics and consciousness.