Here’s where you start building the language you need to understand alchemical texts. To organize this, let’s look at emblem twenty-one of Michael Maier’s Atalanta Fugiens. Maier says we can construct the philosophers stone by “making a circle out of a man and a woman, deriving from it a square, and from a square a triangle, then making a circle”. This is the same sort of breakdown seen in the Pythagorean tetractys or in the Axiom of Maria. The following modules break this whole thing down and get you thinking about the individual parts of the universe.
But that this was not unknown to the Philosophers of Nature is apparent from this: That they command a Circle to be turned into a Quadrangle, and this by a Triangle to be reduced again to a Circle. By a circle they understand the most simple body without angles, as by the Quadrangle they do the four Elements…. In like manner the Philosophers would have the Quadrangle reduced into a Triangle, that is, into a Body, Spirit and Soul, which three appear in the three previous colours before Rednesse: that is, the Body or earth in the Blacknesse of Saturn, the Spirit in the Lunar whitenesse as water, and the Soul or air in the Solar Citrinity. Then the Triangle will be perfect, but this again must be changed into a Circle; that is, into an invariable rednesse…
“One becomes two, two becomes three, and out of the third comes the one as the fourth.” -Axiom of Maria