The book "The 20th Century Idealist" by Henry Pettit reveals the life and thoughts of an outstanding philosopher who influenced the development of the idea of idealism in the 20th century. The author analyzes in detail the main principles of idealism and reveals their importance for the formation of modern philosophical thought. The book in-depth explores Henry Pettit's creativity and influence on the development of philosophy, helping the reader to better understand the essence of his idea and to suggest ways of using it in the modern world. "The 20th Century Idealist" is not only a book about philosophy, but also an invitation to think about your own beliefs and ideals in the context of the modern world.