"The parable of the prodigal son tells the story of a young boy who leaves his paternal home to seek adventure in the world and, having encountered only trials and disappointments, returns at last to his father’s house. All sacred books contain images and accounts illustrating these two processes: going out and returning, involution and evolution.

When alchemists describe the two operations ‘solve’ (dissolve) and ‘coagula’ (condense), it is another way of presenting these two movements of life. Nature herself speaks of this. You are looking at a clear blue sky, and then a kind of veil appears, a condensation (coagula) of water vapour, and clouds form. Some time later, it all disappears (solve), and the sky is blue again. Everywhere in the universe you will find these two phenomena – ascent and descent, appearance and disappearance, birth and death, creation and the return to nothingness – inviting the disciple to pause and reflect."