Introduction to Astronomy

Thus, he who has known all things that produce such principles in composite things may easily understand what comes from elsewhere, which it is necessary to leave to the virtue of the stars. First, we distinguish the four properties of materials by three differences. The first is the contrariety of qualities, such as heat and cold. The second is the resolution of one into another, as earth into water, water into air, air into fire, and so in reverse. The third is the reception of growth and detriment. For one part of the air is more humid than another part, and one part of the earth is more dry than another. There are also three other properties of the form, distinct from these. The first is that there is no contrariety in the form, nor does a man consist of contraries in that which is rational or mortal; he is not contrary to the rational or the mortal. The second is that one form does not resolve into another, as a man never becomes a donkey. The third is that it is capable of neither growth nor detriment; for a man is not more or less rational or mortal than another man. Therefore, we recognize that all these principles exist in all bodies, because in contrary things, that which is resolvable, growing, and decreasing is found; as a man is now hot, now cold, now passing from hot to cold, now more or less hot or cold from matter. But what is opposed to these in their genus is from the form; that which is neither from matter nor from form is present; yet, because there is nothing whose birth is not preceded by a legitimate cause and reason, nor is there anything surviving in the lower part of the world that holds the place of a cause besides this, it is necessary that this follow from celestial power. This, however, is the division and distance of genus from genus, species from species, individual from individual, such as the harmony of soul and body, and other countless accidents; such as ferocity, the discretion of form, the beauty or ugliness of habit, the inequality of stature, various colors, different manners, and the like. Therefore, every individual consists of three principles: the properties of form, the properties of matter, and the effect of the stars. Therefore, those things that arrive according to effect follow their different guidances, some proper and some common; as the sun is the singular guidance of life, general to all animals; Mercury, of man. Since, therefore, the guidance of the stars is conceded for the singular things of the world, it nevertheless assumes in common duties the participation of others; as the sun singularly guides the general substance of one man, and the special. Mercury, however, assumes the counsels of the others in perfecting common things. There will be, therefore, the proper guidance of the sun in one man for the substance of the animal. But the common one is for the heart and brain. The singular guidance of Mercury is for the human substance, with the participation, however, of the mouth and tongue. The light of Ceres is taken in participation; to Saturn, the spleen; to Jupiter, the liver; to Mars, the blood; and thus the rest concede to the others. Thus, in all bodies, each claims its own parts and all properties and accidents by a dual guidance; which, if they did not consist of a different guidance, it would not be possible for them to consist of different parts, qualities, properties, or accidents. Now, however, it is in the guidance of things of the stars: one concedes genus, another species, another the individual, at different times and with different qualities, quantities, and other accidents. This is why we see that contemplations also differ in individuals and their natural properties, and that one precedes another, which is by no means of material or formal power, but of sidereal virtue.