The Philosophers' Child, filius philosophorum (Latin for "the philosophers' child", i.e. made by the true students of philosophy)
In some texts it is equated with the philosopher's stone (lapis philosophorum), but in others it assumes its own symbolic meanings.
Other terms for the filius philosophorum include filius sapientiae ("child of wisdom"), infans noster ("our child"), infans solaris ("sun child"), infans lunaris ("moon child"), and infans solaris lunaris ("sun moon child"). There are several images that have been used to represent the filius philosophorum. Among these are the transformed hermaphroditic Hermes, the child of the Red King and the White Queen (the Sun and Moon), the child of the egg, and the three-fathered Orion.
"We are Father, Daughter, and Son in one being. Yet they seem not much alike together. The Holy Trinity."
Born from the two mountains: Mercury & Venus
(bottom caption) And it (the philosophical child) is born in two mountains with battlements set. (left figure) Whose father is a maiden ( = “magt,” maiden/virgin). (right figure) The mother conceives not.
Such paradoxa of generation are a hallmark of alchemical rhetoric: they assert that the stone is born from contraries united in one matter: a “father” that is maidenly and virginal, and a “mother” that does not conceive in the ordinary way. Mercurius is both male and female, a duplex substance that unites opposites
This motif also appears verbatim in Michael Maier’s Atalanta fugiens, Emblem XXXVIII: “Rebis, ut Hermaphroditus, nascitur ex duobus montibus, Mercurii & Veneris.” “The Rebis, like a hermaphrodite, is born from two mountains, of Mercury and Venus.”