On Minerals

...not according to species, but rather as certain "passions" In medieval philosophy, a "passion" refers to a property or state that matter undergoes or receives, rather than its essential identity of matter; for instance, they believe stones have hardness as a form, just as is determined in the book of Metaphysics original: "lib.metb."; referring to Aristotle's Metaphysics. Coagulation and the effects of coagulation are species and passions of matter, and not substantial forms. Those who hold this opinion also argue from the operations of alchemists, who see that stones and metals are made and generated by the heat of roasting through one such effective agent. They argue this because they believe it is not necessary to have a specific creative power in nature where nothing leads to a "substantial species" substantial species: the essential nature that makes a thing what it is (e.g., what makes a diamond a diamond and not just hard carbon) due to the lack and defect of the species itself. But from this follows an intolerable error:

Refutation

namely, that every stone would be of the same species as every other stone, and they would only differ by being "more or less" of that same material. For all these thinkers have taken coagulation and its result—hardness—to be the species itself. But the diverse virtues and operations of different stones show that this is false, for these qualities follow entirely different species of stones. Furthermore, if they were correct, stones would have to be of the same species as metals, since both are created through coagulation and hardness. Moreover, if there were no efficient cause of stones except for drying heat, then every stone would be dissolved by cold moisture, just as we proved in the fourth book of Meteorology original: "quarto metb."; referring to Aristotle's Meteorologica, which we do not see happening. These, therefore, are the opinions spoken in error by the ancients concerning the generative cause of stones.

Chapter Five: On the effective cause of stones according to the true opinion, and on its proper instrument.

The generative cause of stones

We, however, gathering the true opinion from all of these, say that the most truly generative cause is the formative mineral power of the stone. For the mineral power is a certain common power that produces stones, metals, and those things that are intermediate between them. And therefore we add that it is "formative of the stone" so that it may produce a specific stone. Because we do not have proper names for this power, we must clarify what it is through similarities. Let us say, therefore, that just as in the seed of an animal—which is the surplus of nourishment descending from the seminal vessels—there is a formative power which shapes and produces the animal (and is present in the seed in the same way an artisan is present in the object he creates), so too, in matter prepared for stones, there is a power forming and producing stones and leading them to the specific form of this or that stone. This can be seen more clearly in the gums that drip from trees; for we see that these are moisture heavily affected by terrestrial dryness, and therefore they are coagulated by cold. When they remain in the tree without dripping out, the "path" of the tree generates them into wood, leaves, and fruit. In entirely the same way, when dry matter is affected by oily moisture, or moist matter is affected by terrestrial dryness, it is prepared for a stone and generates within itself—from the power of the stars and the location, as will be shown below—the formative power of stones, just as it

is generated in the seed by the testicles when the seed has been drawn to the seminal vessels, providing each matter with its own proper species-power. And this is what Plato said: that according to the "merits" of the matter, celestial powers are infused which perform the works of nature. However, as we have shown in the books of physics, every power that forms and makes something according to its species has a proper instrument by which it does its work. Therefore, this power existing in the proper matter of stones has two instruments according to the diversity of nature:

Plato.

Two instruments of the power.

The first.

The second.

Aristotle.

1. One is a moist heat, which extracts and digests, inducing coagulation toward the form of stone in terrestrial matter that has been affected by oily moisture. The formative power directs this heat in its work, just as the heat that transforms an animal's seed is directed by the formative power within that seed. For otherwise, without doubt, if that heat were excessive, it would incinerate the matter; or if it were insufficient, it would leave it undigested and unsuitable for the form of a stone.
2. The other instrument is found in the matter of watery moisture which has been affected by terrestrial dryness, and this is a moist cold. This does not just restrict the material (as happens in metals), but actually "expresses" squeezes out the moisture. This hardens and coagulates most vehemently. And because it expresses the moisture so entirely that none remains except for what is needed to hold the substance together, such stones can in no way be melted by dry heat.

And this is what Aristotle says: that crystal is generated from water once the heat has been universally removed. The proof of this is that the operations of alchemists fail in melting stones without adding other moist matter. It is also clear why the operations of alchemists are often difficult and imperfect in the making of stones, even more so than in metals. This is because they do not give a "formative power" to the matter; instead, they use uncertain art in its place. For them, extreme heat is their instrument, and this operates most unreliably. However, the power given from heaven to a specific place and matter—which is called "formative"—is certain. The matter is suited to the instrument, and the instrument to the matter. Therefore, nature is most certain in its operations. There is one other thing to note: although coldness is never the cause of life in living things, it does work to create stones, because minerals are very close to the basic elements, and their qualities remain little altered.

Chapter Six: On the substantial form of stones.

Debating about the forms which are the "substantial essence" of stones seems to be the act of a madman, since our own sight confirms that they are all coagulated, and the matter in them is determined toward a certain species. For if they were only various arrangements of the elements...