Doctrine has neither been invented nor exaggerated, but, on the contrary, simply outlined; and finally that its teachings antedate the Vedas. This is no pretension to prophecy, but simply a statement based on the knowledge of facts. Every century an attempt is being made to show the world that Occultism is no vain superstition. Once the door is permitted to remain a little ajar, it will be opened wider with every new century. The times are ripe for a more serious knowledge than hitherto permitted, though still, even now, very limited. For have not even the _Vedas_ been derided, rejected and called “a modern forgery” even so recently as fifty years ago? Was not Sanskrit proclaimed at one time the progeny of, and a dialect derived from, the Greek, according to Lemprière and other scholars? About 1820, as Prof. Max Müller tells us, the sacred books of the Brâhmans, of the Magians, and of the Buddhists, “were all but unknown, their very existence was doubted, and there was not a single scholar who could have translated a line of the _Veda_ ... of the _Zend Avesta_, or ... of the Buddhist _Tripitaka_, and now the _Vedas_ are proved to be the work of the highest antiquity, whose ‘preservation amounts almost to a marvel’.” The same will be said of the Secret Archaic Doctrine, when undeniable proofs are given of its existence and records. But it will be centuries before much more is given from it. Speaking of the keys to the Zodiacal Mysteries as being almost lost to the world, it was remarked by the writer some ten years ago in _Isis Unveiled_ that: “The said key must be turned seven times before the whole system is divulged. We will give it but one turn, and thereby allow the profane one glimpse into the mystery. Happy he, who understands the whole!” The same may be said of the whole Esoteric System. One turn of the key, and no more, was given in _Isis Unveiled_. Much more is explained in these volumes. In those days the writer hardly knew the language in which the work was written, and the disclosure of many things, freely spoken about now, was forbidden. In Century the Twentieth, some disciple more informed, and far better fitted, may be sent by the Masters of Wisdom to give final and irrefutable proofs that there exists a Science called Gupta Vidyâ; and that, like the once mysterious sources of the Nile, the source of all religions and philosophies now made known to the world has been for many ages forgotten and lost to men, but it is at last found. Such a work as this has to be introduced with no simple preface, but with a volume rather—one that would give facts, not mere disquisitions, since THE SECRET DOCTRINE is not a treatise, or a series of vague theories, but contains all that can be given out to the world in this century.