The book "Sex - Unknown Value: The Spiritual Function of Sex" by Alexander J. McIvor-Tyndall is a guide to the world of the mysterious and powerful force called sexuality. The author studies sex as a spiritual tool that can contribute to the evolution and harmony of relationships. It goes through ages and cultures, considering the sexual act as a mechanism of connection between the physical and spiritual worlds of man. Through the transparent view of the author, you will be able to better understand the depth of sexuality and its potential for self-awareness and spiritual development. "Sex - Unknown Value" is an invitation to study sex as a key aspect of human existence from the point of view of its spiritual significance.