Tetrabiblos (The Quadripartite Book)

...to gloss the words of Ptolemy, intending to place his own from one side and the glosses from another, so that the book might be well divided.

Chapter 1 of the first treatise of the Quadripartitum of Ptolemy, on the collection of the understanding of the science of the judgments of the stars.

Prologue.

Decorative drop cap 'R' with ornate floral and foliage patterns contained within a rectangular frame.
We determine that there are two greater and more noble things among the matters in which the science of the prognostication of the stars consists.

R

C The things by which the prognostication of future events is perfected are two, and they are the greater and the more noble.

C

C Ptolemy looked into all manners of prognostication and found them to be defective and the sons of all others who had spoken concerning such things. And he found that each one in his own science was aided by the stars; just as Hippocrates spoke concerning the rising, descent, and setting of the stars; and just as Galen spoke concerning the mutations of infirmities which follow the courses of the moon; and just as laborers who know the time when they ought to plant trees and vines, and [those who know] how to give the male to the female among beasts. Similarly also sailors direct their ships by the stars; [likewise] men and laws in ordering their boons, hours, and feast days. Yet in all these things, whatever they have of the science of the stars is a very small thing, so that it does not suffice. And perhaps it happened that only the astrological art is the full [science] of prognostications, for the astrologer knows what all these [others] know, and beyond that, [he knows] what is lacking to the completion of the whole. And on account of this, Ptolemy said: the things by which the art of prognostication is perfectly completed are two, and these two are greater and more noble. And what are these two? The quadrivial astrology and the art of the judgments of astronomy. C That he said "of future events," he wishes to say "of all future things," and he says this so that he may do honor to those reading his book; and you will find such a word of courtesy at the beginning of all his books, as in the Almagest and the Arithmetic. C That he also said "greater," he wishes to say "of greater perfection," because the perfection of any science ought to be such that it is true, comprehending all the reasons that follow from it. C But that he said "more noble," he said it because the matter of which the quadrivial science speaks are the celestial bodies, and the matter of which the judgments of astronomy speak are all bodies existing below the sphere of the moon, and for that reason this art is more noble than all others, because the matter of which it speaks is the whole world. Nor, however, are the words which Ptolemy said one argument, the subject of which is that which he said: that the things by which the prognostications of future events are perfected are greater and more noble, and the predicate is that which he said: "they are two."

C Of which the one that precedes and is stronger is the science of the sun and the moon, and also of the figures of the five erratic stars, which it is manifest to touch as the cause of their own motions, and in the comparison of one to another of them and to the earth.

C One of which is that which is to be set forth in ordering and virtue, and it is this art by which the figures of the two luminaries and the five planets are known according to their motion in comparison of one to another, and of them to the sphere of the earth.

C This is the quadrivial astrology, because by it a man knows the figures of the stars according to their motions and the respect of one to another. And these figures are conjunctions and other aspects, in comparison of their aspect to the earth, or which are around the earth or far away, or when they rise or set in the eclipses of the two luminaries, and the like. And on account of this, Ptolemy said "figures of the stars" so that he might make us understand that the science of knowing whether natures are light or not, if they are heavy or not, is not of the science of astrology, but is of the science of natures. And the five planets of which he spoke are Saturn, Jupiter, Mars, Venus, and Mercury. C And that he spoke of the art of astrology which was to be set forth in ordering, [it is] because if we do not know the figures of the stars, we will not know how to judge according to how they operate in inferior bodies. C And that he spoke in virtue, it was because these demonstrations are firmer and stronger than those which are in the art of the judgments, and this [is] because they are taken from geometry and arithmetic. C Furthermore, because the matter of which it speaks is more noble than that of which this other speaks, since that one is celestial, [while] this one is terrestrial. But he spoke only of the seven planets and did not name the fixed stars, and this because the planets are of light motion and are quickly changed from one state to another, and [it is] because this inferior body is changed, and especially because the virtues of the fixed stars follow in comparison of them to the virtues of the seven planets. And always when Ptolemy names the two luminaries, he says "the sun and the moon," and when he names other planets, he says "such a planet and such a planet," so that he may make us know their virtues. And if you look to his words, you will find that he himself names them so. C The second thing which is desired is the mutations and works which happen and are perfected by the figuration of the courses of the stars, in that they are their own natural [motions] and by the great prerogative which the two great luminaries have over other planets, and in the things which they comprehend. And it is the science of the judgments of astronomy, because by it a man can know the mutations and works happening in things which are towards us. And the mutations of which he spoke are always manners of motion, which are: generation, conversion, corruption, augmentation, and decrement, and mutation from one place to another. And the works which he said are things coming from these mutations in the manner of a consequence, just as the virtues of the soul follow the complexion of the body. C And that he said "happen and are completed," he said it to express that things which are made are not yet completed, just as time which is always being made and is never completed; in knowing, however, what time is and why it comes, this is not of this science, but of the science of natures. C But if someone should form an argument about this, saying that Ptolemy has already spoken in this science of a thing which is made and not completed, as when he spoke of the aborted [fetus], we respond to this: that the aborted fetus has already been completed in all its members, yet the time of its life was not completed.

C That, however, he said "by the figuration of the courses of the stars," he said it for this reason: that each planet has its own proper course. And on account of this, each of them is separated into a figure separated from the figure of another, because he who at one time is oriental, at another is occidental, and he who is occidental becomes oriental, and so in other figures. For on account of such figures, works and mutations happen in the things which are towards us, and they have this from nature, just as the adamant stone draws iron to itself, and just as scammony purges bile, and other such things.

C The other, truly, is the science by which are explained the mutations and works which happen and are completed on account of the figures of their circuits natural to them in the things which they surround. But since of the two aforementioned, the first which is the science by itself, and the other is committed to it, so that the seeker of science may perceive its cause and learn it and receive this fruit, even if he does not learn the second science. It is therefore manifest that this is so, for we have already made for you a volume of the first science by itself, in which we have proceeded reasonably to the extent of our power.

C The first of the two sciences which we have spoken of is the science separated and completed by itself. And it is such that a man ought to learn it because of the profit which is in it by itself, without interfering with this other, because he can excuse this other second one of which we have spoken. And because it was the first of our proposal that it be so, we have composed this book separated from the first science. We have proceeded, indeed, in the first way of demonstration according to our power.

C After Ptolemy said that the science of the judgments of astronomy ought to be read after the quadrivial astronomy, he notified to us the virtue which is in each of them, so that no one might estimate that the purpose of the quadrivial science is only so that it may arrive at the profit of the judgments of astronomy. And on account of this, he said that the quadrivial astrology is a thing which can be to the end of its own purpose, without this [one] of the judgments. For indeed the book separated which he said he had composed in astrology is the book of the Almagest.

C In this book, we will explain the second science by itself, which is by no means explicable [on its own], as physical reason demands.

C The second thing which we have spoken of is not completed by itself, but we wish to speak of it in this book according to the way of philosophy.