Geometry, Socrates says in Plato's Republic, forces the soul to contemplate the essence of things. It attracts the soul towards truth and develops that philosophical spirit that elevates our gaze towards higher things. Proclus, on the other hand, in his work on Platonic theology, adds that the first way of revealing divine principles through symbols belongs to Orpheus and generally to those who convey divine myths in written form. The second way, with the help of images, belongs to Pythagoras, because as he says: "the discovery of mathematics was made by the Pythagoreans in order to remember the divine principles which, with their help, they sought to ascend to higher causes. That is why they dedicated numbers and geometric shapes to the gods." In this book, Dimitris Evangelopoulos describes the various theories about Sacred Geometry and analyzes them practically, presenting the numbers and shapes that constitute our visible and invisible life and world.