The practical development of harmonics was facilitated by Addey's use of computers. Nevertheless, the initial vision of a basis for a rational astrology arose from a vantage point of Platonic and Pythagorean contemplation. For Addey, the value of astrology was as a way of seeing the great order of time as expressive of eternal forms and numbers. The value of the natal chart was that it was, in his words, “a diagram of the soul’s contract with time and space”. He was influenced by Plato's myth of Er described in The Republic, in which Plato suggests that the soul continually incarnates having made a positive choice to take on the opportunities and challenges of a particular terrestrial life, lived at a particular time, in a particular place.