What is alchemy? Where does it come from and what is the content of its teachings? Quite a few scholars like Albertus Magnus, Thomas Aquinas, Johann Wolfgang von Goethe, Athanasius Kircher, Paracelsus and Isaac Newton dealt with alchemy. No other phenomenon is so richly laden with legends, pictures and secret writings about the alleged Homunculus, gold production or the Philosopher's Stone. Despite its occult methods and dubious practices, alchemy is the forerunner of our industrial chemistry today. So what's this secret doctrine all about? Minutiously, this work tried to determine the spiritual roots and to classify and name them in the light of the Christian faith. This book has been translated with Artificial Intelligence.