""Ancient Wisdom: The Mental Plane"" is a book written by Annie Besant, which explores the concept of the mental plane in ancient wisdom. The book delves into the teachings of various ancient civilizations, including Hinduism, Buddhism, and Theosophy, and examines their understanding of the mental plane as a realm of thought and consciousness. Besant discusses the different levels of the mental plane, including the higher and lower levels, and explains...