Tetrabiblos (The Quadripartite Book)

He says that the first reason because of which some believed that this art cannot be attained is: because some astrologers do not look into it, nor do they study in it as they ought, and they pass over the things which are in this art, which to do is not as they ought, because it is an art of great diversities and of many paths. Wherefore it is accustomed in knowing it, that it has great labor and study. And because to some not studying in it as they ought it happens to err with many errors, those who see them err thus believe that the things which they certify sometimes happen by fortune, and not by a right and firm root of this art.

¶ But this occasion of theirs is inconvenient. Because this deception does not happen due to the weakness of this art, but due to the temerity of those who look into it.

¶ This, indeed, which they estimate is not true. And the error by which some err in this science is not from the weakness of the art, but of him who meddles in it.

¶ Ptolemy destroys the reason of them with this occasion, saying that the error which happens to some astrologers is not from the weakness of the art, but from the laziness and negligence of some who meddle in it. And after it is so, it is manifest that the things which are certified by this art do not happen by chance, but by true roots and firm and certain rules, just as he showed before.

¶ The second occasion, indeed, is this: there are very many who, in order that they might earn much, having a prediction of another doctrine, attributed the cause to this science, by whom many deceived were driven to this opinion, so that by the force of this science they might predict many things, so that in opining they exceeded the mode of its nature.

¶ Another reason indeed is because, in order that they might earn much, they take predictions from another part, saying that they know the predictions themselves through this science, and they place them into the sophistry and error of the people, making them believe that they know future things, and many and miraculous ones, to such an extent that they pass on to speaking of things which are not in nature, which no one can know.

¶ This is the reason that many believe that the science cannot be attained, so that we find cities full of men who pretend to know the art of astronomy, but are much removed from it, and they place into the sophistry and error of the people, making them believe that they know many miraculous things from those things which are to be, and they are so bold that they speak of things which are not of the nature that human intellect can attain them. And I wish to give you an example of one of these such men whom I saw.

¶ A certain man came to us who held himself for a great philosopher, and he told us great reasons of marvels, how you should know that the horn of Leo has arrived at the 15th degree of Leo, and there will not be fire in Leo which may burn the whole world. I, however, when I heard him, laughed at him. Yet others who stood there said: "It is accustomed that you do not care much about saying such words." And what seems to you when he descends to speaking of the nativities of those who make chronicles, that he said that Mercury was in the nativities of men in the degrees which are called "pits".

¶ For this is done that sometime it will be in the intellect, and this is the greatest ignorance that can be by many reasons. One, because the degrees of the pits are the vilest that can be. Second, because they place their science into bad fame and by meddling in it. Third, if it were well true that which he said, Mercury could be in that misfortune by the aspect of other planets. And I would wish to know whence he learned this and received it, or how he could have experience of this without others who were before him. This indeed is said by Abumasar that it is a phantasm from those things which we know in other of his works, because perhaps he found Mercury in his nativity or another's informed in the degree of the pit. We know, indeed, that Abumasar, before he read astronomy, was one of those who were making chronicles, such as we find in scriptures; and for this he believed that all others who were making chronicles had such a sense as he himself. And how can this be true, that those making chronicles should have a defect of intellect? Because we have already found many of them of good sense and intellect, and from them we have received certain doctrines of those things which have passed. And I saw one knowing something of the science of astronomy who came to me one day saying to me that he heard one saying that he himself knew much of this science and could foreknow things which no one in the world could know. This man, indeed, said to me: "How can one know when Mars enters the second house of the nativity of anyone, that his own garments would be stolen from him, but other clothes [would remain]?" And he did not seek another, that is, [further] inquiry. To whom I said that this is a thing which a man thus separately cannot know through this art. He said to me afterward: "Our companion pretended to know such a thing with great lying." Wherefore for such things some believed that this science cannot be attained; they cast it out for that reason. And you will understand that many for this reason cast it out when you read the fables of the books which such as these make, [which are] profane, that is, phantasms, so that they may show themselves wise, who impeded us with many words and disturbed us from knowing the truth. I say, indeed, that when I see much and through many I find it impeded, I exonerate myself from it, nor do I wish to draw myself to them; and I altogether advise you that you sustain your will, nor do you wish to labor in those books of theirs, nor meddle yourself in them, but apply your mind and study in the path only of Ptolemy, because it is the right and certain path and a thing certified by proof of arguments and true experience, so that there is no doubt in it.

¶ Wherefore this work of theirs was the occasion that many might vilify not only what can be known from it, but also that which is knowable.

¶ And for this which they do, some of them found reasons by which they could understand the things of this science which are in nature, that a man could know them without studying in them, and they cast them out just as they cast out the things themselves, estimating that all are vain.

¶ He says that such deeds as those committed whom we spoke of before, made the students, who could know something, cast out this science, much more those who, not studying in it, have no will, estimating that whatever is contained in this art is all of the manner of phantasms, which those men said. And I saw some students who could know something, to whom this happened. I saw, indeed, some of them who studied in the books of the "thousands" and the "hundreds" and the "tens," and believed that it was certain and true whatever was spoken there by Abumasar and the like. And they wished to test this in past things, and there they found no certainty. And I said: "Great confusion is of you, because you leave looking into the motion of the stars and the great things, and you wish to know those things which are to be through the count of years." Because if this were true, the art of astronomy, and those things which we can know through the stars about that which is to be, would be nothing. I believe for certain, indeed, that such things as these are outside the rule of this art, which some extracted to place others in error, and to attribute to themselves praise of a thing in which there is no truth. For all these are things about which they have a will that those who hear them [believe them], as of fables which never were; and they believe that it is a great thing. And of the sophistries which are reasons which seem to be thus, and when a man searches them out in rectitude and truth, he finds them all liars. And they believed that whatever was said in this art was of the same manner. And if those who spoke such new things did not extract them, but believed that they were true, it is the greater ignorance that they compiled books thereof and filled parchments with lies, knowing how they were spending their time in lies and vanities.

¶ This occasion also, as the first, is inconvenient. For not because of the ignorance of fools is philosophy to be vilified.

¶ And because of this, it is not right to cast out philosophy and to leave it because of the malice of some who pretend to know them.

¶ He says that this which some estimate, that whatever is said in this science is of one manner, is not right nor does it follow. Because in this [science], if one will have looked well into it, he will not find any defect. But the defect is in those who pretend themselves of it and place things there which are not of it, nor pertain to it. Because thus it does not follow that philosophy is to be cast out nor rejected because of the malice of some who pretend themselves of it. Similarly, it does not follow that this be depreciated, nor cast out for the same reason.

¶ It is manifest that the searchers of the sciences, good and accurate, are sometimes not deceived because of the aforesaid occasions, but because of the nature of the thing itself and its own weakness, because a thing