The Blood And Tongue of the Dragon
Arcane magic flows from dragons. While other sources may steal and grant this power, such as demons or fey lords, it is a power that flows from the dragon’s tongue. It is to speak and sing in the harmonic flow of their voice, or to dance with the power of their blood.
Curiously, only women can channel the power of the dragon through blood. For whatever reason, men do not carry the blood of dragons in their veins. Unless they are born a half dragon, a man cannot come to wield magic innately, yet women can. Women are attuned to the male aspects of dragons, and so, if a woman has draconic heritage in her, she is capable of becoming a sorceress.
Because they can legitimately claim descent from dragons, women who show sorceress potential are in a higher social category than all other humans. They are often deemed suitable mates for dragons and even a married sorceress is expected to bear a dragon’s child, if she is so chosen.
The draconic law forbids women from learning the arcane arts through wizardry. Though in places further from the reach of draconic civilization, this law is a little lax, a woman found to be practicing wizardry will be executed. This is so that there is no confusion with sorceresses and inferior breeding stock is not allowed in high draconic society.
This is usually practiced throughout the world, so the overwhelming majority of wizards are men.