If the genera are the great universes of the structure, the species are the concrete forms in which those universes appear in a person. It is not enough to say that someone belongs to the choleric, sanguine, phlegmatic or melancholic universe, because the concrete person rarely appears in a pure genus, without modulation. What they usually show is a main matrix and a secondary modulation that considerably changes the way that matrix expresses itself. This is what the method calls a species, and here it goes beyond the simplified traditional classifications.
The species is not an external detail but the actual form of the structure, and it answers the question: how does this genus really appear in this person? In its most direct form, or crossed by a second, neighboring force that changes its expression? In Axis Ratio, there are twelve valid species, four pure and eight mixed.
The pure species are the pure choleric, the pure sanguine, the pure phlegmatic and the pure melancholic. They represent the simplest and most easily recognized form of each genus. "Pure," here, does not mean perfection, greater intensity or lack of complexity; it only means that the genus appears with less modulation from another matrix.
The mixed species are eight:
- choleric-melancholic;
- choleric-sanguine;
- sanguine-choleric;
- sanguine-phlegmatic;
- phlegmatic-sanguine;
- phlegmatic-melancholic;
- melancholic-phlegmatic;
- melancholic-choleric.
None of these mixed species is "half and half," and understanding this avoids a good share of the errors in reading the method. The person is not a collage of traits but a unity. When we say "choleric-melancholic," we do not mean that the person is fifty percent one and fifty percent the other, but that the dominant matrix is choleric and that the melancholic modulates it from within, producing a new form, one and irreducible.
That is why the order of the name matters. Choleric-melancholic is not the same as melancholic-choleric, just as sanguine-phlegmatic is not the same as phlegmatic-sanguine. In the first position is the dominant universe; in the second, the force that modulates it. This changes the style of the energy, the shape of the fall, the main fear, the thesis of the self, the kind of suffering and the path of purification. Without this rule, the mixed species would become a sum of adjectives; with it, they become real and precise forms of the human structure.
It remains to ask why there are these eight mixed species and not any other combinations. The answer is that the method does not combine in the abstract but follows the continuity of the wheel: mixed species arise only between neighboring genera, never between opposites on the same axis. That is why there is no valid species such as "choleric-phlegmatic" or "sanguine-melancholic," because those pairs are not living neighborhoods but structural oppositions. The mixed species appear in the passages between choleric and sanguine, between sanguine and phlegmatic, between phlegmatic and melancholic and between melancholic and choleric. The mixed species, then, is not an accidental blend but the unified form of the tension between a dominant matrix and a neighboring one, and the whole system is organic: the species are born of the logic of the wheel, not improvised.
In practice, this means that each species has its own energy, a particular way of reading the world, a way of suffering, a main fear, a thesis of the self, a most likely vice, a form of compensation and its own path to maturity. The genus is necessary but not enough, because it shows the universe; the species shows the person in their most determinate form. It is in the species that the soul takes on an outline, and it is there that the theory finally touches the concrete life of whoever studies it.
How to read the twelve species
Before describing each species, it is worth setting down four rules of reading, because without them any description turns into a horoscope. The first is that, in a mixed species, the first name gives the end and the second serves it: in the choleric-sanguine, people serve effectiveness; in the sanguine-choleric, effectiveness serves presence. The second is that the same trait can serve different ends, and so no isolated act, no leadership, no shyness and no outburst is enough to classify anyone; you have to see the same person in many situations, above all in those where two goods come into conflict and one of them has to give way. The third is that maturity does not change the species: a choleric-sanguine saint is still choleric-sanguine, and a description that held only for the fallen person would be describing the vice, not the temperament. The fourth is that the temptations described are maps, not diagnoses: they say where each form is usually tested, not that anyone has fallen, and no one is free of the vices that do not appear in the description of their species.
In chapters 11 to 14, each genus is presented first and, right after it, the three species it governs. For each species, the course is the same: what it is and which image represents it, how it appears in life, how to tell it apart from its inverse pair, the good proper to it, the temptation proper to it and its mature form.