Apparently but few of the medieval alchemists discovered the Great Arcanum without aid, some authors declaring that none of them attained the desired end without the assistance of a Master or Teacher. In every instance the identity of these Masters has been carefully concealed, and even during the Middle Ages speculation ran rife concerning them. It was customary to call such illuminated sages adepts, a title which indicated that they possessed the true secrets of transmutation and multiplication. These adepts were polyonymous individuals who unexpectedly appeared and disappeared again, leaving no trace of their whereabouts. There are indications that a certain degree of organization existed amoung them. The most powerful of the alchemical organizations were the Rosicrucians, the Illuminati, and certain Arabian and Syrian sects.