The transformation of Mercurius, as prima materia, in the heated, sealed vessel is comparable to cooking the basic instinctive drives in their own affect until their essential fantasy content becomes conscious.
“Instead of arguing with the drives which carry us away, we prefer to cook them and . ask then what they want. . . . That can be discovered by active imagination, or through experimenting in reality, but always with the introverted attitude of observing objectively what the drive really wants.”
Marie von Franz, Alchemy, p. 129)