Plato, Symposium
“For our ancient nature was not what it is now, but of another kind. In the first place, there were three sexes among men, not two as now, male and female, but a third sex in addition, being both of them in common, whose name still remains though the thing itself has vanished; for one sex was then derived in common from both male and female, androgynous both in form and name, though the name is now applied only in reproach.
Again, the form of each human being as a whole was round, with back and sides forming a circle, but it had four arms and an equal number of legs, and two faces exactly alike on a cylindrical neck; there was a single head for both faces, which faced in opposite directions, and four ears and two sets of pudenda, and one can imagine all the rest from this. It also traveled upright just as now, in whatever direction it wished; and whenever they took off in a swift run, they brought their legs around straight and somersaulted as tumblers do, and then, with eight limbs to support them, they rolled in a swift circle.
The reason there were three sexes of this sort was that the male originally was the off spring of the Sun, the female of the Earth, and what has a share of both of the Moon, because the Moon also has share of both. They were spherical both in themselves and in their gait because they were like their parents. Well, they were terrible in strength and force, and they had high thoughts and conspired against the gods, and what Homer told of Ephialtes and Otus is told also of them: they tried to storm Heaven in order to displace the gods.
Now when their nature was divided in two, each half in longing rushed to the other half of itself and they threw their arms around each other and intertwined them, desiring to grow together into one, dying of hunger and inactivity too because they were unwilling to do anything apart from one another. Whenever any of the halves died and the other was left, the one left sought out another and embraced it, whether it met half of a whole woman-what we now call a woman-or of a man. And so they perished.
But Zeus took pity and provided another device, turning their pudenda to the front – for up till then they had those on the outside too, and they used to beget and bear children not in each other but in the earth, like locusts – well, he turned them to the front and so caused them to beget in each other, in the female through the male, for this reason: so that if male met female, they might in their embrace beget and their race continue to exist, while at the same time if male met male, there’d at least be satiety from their intercourse and they’d be relieved and go back to work and look after the other concerns of life. So Eros for each other is inborn in people from as long ago as that, and he unites their ancient nature, undertaking to make one from two, and to heal human nature.”
Plato, Symposium
Of course modern humans and all their social engineering and brainwashing believe when Plato talks about three sexes he is relaying that there was a third "transsexual" gender.
However Plato's teachings regarding the Twin Souls is showing that the third sex relates to them when they are still in a state of androgyny. The Zohar teaches that when every soul is created, it is created whole (androgynous) then it splits to male and female to be birthed into a biological sheath. That's why Plato says the third sex disappears, because once the Whole "androgynous"Soul is split they are never fully androgynous again.
When a soul comes down from Heaven, it is both male and female. The male aspects enter a male child and the female aspects enter a female child. If they are deserving, God will cause them to find each other and to join in marriage. This is a true union - The Zohar
"No female or male soul is a complete human soul without the other. Male and female are halves of the same whole. What affects one, therefore, affects the other. This becomes most clear when it comes time for joining." - The Zohar
"As they set out from their place above, each soul is male and female as one. Only as they descend to this world do they part, each to its own side. And then it is the One Above who unites them again. This is His exclusive domain, for He alone knows which soul belongs to which and how they must reunite." - The Zohar
“Fashion two images with the 1st face of Cancer rising, and Venus therein, and the Moon in the 1st face of Taurus in the eleventh house. And when you have made these images, join each to the other face to face and bury them in the house of the other . And they will care for each other and have an enduring love between them” - Picatrix: Arabian - 10th or 11th century
"They are not said to be husband and wife who merely sit together. Rather they alone are called husband and wife, who have one soul in two bodies." - Ram Das, Sikh Gurū and Mystic (1534 – 1581)
