Once upon a time, in medieval Germany, there lived a pious and mystical scholar named Rabbi Eliazer ben Judah of Worms. Now, the most awesome feat for any mystic is creation. Actually, the medieval magician owed his creative powers to demons, and it is well known that demons cannot create anything smaller than a barleycorn and that they cannot create anything that is complex, like camels, camellias, or chamomile. Anyway, this was for profane earthly magic. On the other hand, old Rabbi Eliazer was a holy man, and the Talmud recognizes a second method, a more holy method, of creation.
Sacred creation avoids demons and other spirits.
By means of these Laws, one might create an entire world, inhabited by men and other living creatures. No one knows for certain, but Rashi has suggested that these rabbis discovered how to combine the letters of the Ineffable Holy Name. Later, after the Dark Ages had begun to fade, Rabbi Eliazer ben Judah learned the holy rules of creation too. Well, the ten basic words were told to him in a dream by the angel Aniel. But the Rabbi himself spent many hours studying these words and reflecting on the most difficult passages in the original Kabbalist book, the Sefer Yetzirah.