"Magic is a dual power: nothing is easier than to turn it into Sorcery; an evil thought suffices for it. Therefore while theoretical Occultism is harmless, and may do good, practical Magic, or the fruits of the Tree of Life and Knowledge, or otherwise the “Science of Good and Evil,” is fraught with dangers and perils. For the study of theoretical Occultism there are, no doubt, a number of works that may be read with profit, besides such books... in Latin by the mediaeval Philosophers, generally known as Alchemists and Rosicrucians, are plentiful. But even the perusal of these may prove dangerous for the unguided student. If approached without the right key to them, and if the student is unfit, owing to mental incapacity, for Magic, and is thus unable to discern the Right from the Left Path, let him take our advice and leave this study alone; he will only bring on himself and on his family unexpected woes and sorrows, never suspecting whence they come, nor what are the powers awakened by his mind being bent on them..."