Ever since the Timaeus it has been repeatedly stated that the soul is a sphere.
As the anima mundi., the soul revolves with the world wheel, whose hub is the Pole.
That is why the “heart of Mercurius” is found there, for Mercurius is the anima mundi.
The anima mundi is really the motor of the heavens.
The wheel of the starry universe is reflected in the horoscope, called the “thema” of birth.
This is a division of the heavens into twelve houses, calculated at the moment of birth, the first house coinciding with the ascendent.
Divided up in this way the firmament looks like a wheel turning, and the astronomer Nigidius is said to have received the name Figulus (“potter”) because the wheel of heaven turns like a potter’s wheel.
The “thema” (that which is “set” or “ordained”) is indeed a ‘wheel’.
The basic meaning of the horoscope is that, by mapping out the positions of the planets and their relations to one another (aspects), together with the distribution of the signs of the zodiac at the cardinal points, it gives a picture first of the psychic and then of the physical constitution of the individual.
It represents, in essence, a system of original and fundamental qualities in a person’s character, and can therefore be regarded as an equivalent of the individual psyche.
Priscillian (d. 385) evidently took the wheel in this sense. He says of Christ: “He alone has the power to join together the Pleiades and to loose the bands of Orion.
Knowing the changes of the firmament and destroying the wheel of generation, he has overcome the day of our birth by the renewal of baptism.”
From this it is plain that in the fourth century the wheel of birth was in fact regarded as the horoscope.
“Setting fire to the wheel” is therefore a figurative expression for a catastrophic revolt of all the original components of the psyche, a conflagration resembling panic or some other uncontrollable, and hence fatal outburst of emotion.
The total nature of the catastrophe is explained by the central position of the so-called “tongue,” the diabolical element whose destructiveness is an essential part of every psyche.
Seen in this light, the Stella marts stands for the fiery center in us from which creative or destructive influences come. ~Carl Jung; Aion; The Fish in Alchemy; Pages 136-137.