The rivers Euphrates and Tigris (Hiddekel) rise in Armenia, which is supposed to be the land of Ararat of Bible history.
The Hiddekel symbolizes the great nervous system in man; the Euphrates symbolizes the circulatory system of man.
The central nervous system lies very close to the mental and spiritual; the circulatory system is more in the region of the physical. Thus the realm of which Ararat is symbolical (the unknown) is the source of both the mental and the physical of man.