Chapter V — On judicial astrology, or divination by the stars

I. Theologians distinguish a twofold astrology: one natural, whereby men foretell, from the motion, rising, position, and setting of the stars, those things which occur naturally — such as rain, storms, and eclipses. This is acknowledged by all to be lawful, together with St. Thomas (II-II, q. 95, art. 5), who, after reviewing various views, concludes as follows: "If someone makes use of the observation of the stars in order to foreknow future bodily effects, caused by celestial bodies — such as drought or rain — this will be neither an unlawful nor a superstitious divination." Although this is absolutely true of those effects which necessarily follow from the position and aspect of the stars and planets, nevertheless, as to storms, droughts, rains, fair weather, and other such things to be foretold — such an astrology is generally vain and useless, though not harmful, both because the power of the stars is not fully known, and because of the obstruction of winds, vapors, and other things, which often impede the influence of the stars. This is well established and proven by experience. Nor do the almanacs published yearly certainly predict any outcome other than the emptying of the purses of the ignorant and unlearned, as the aforesaid theologians of Salamanca observe. I am often inclined to laugh at those who waste their time and money hunting down these trifling pamphlets, and who read and reread them with such curiosity and greed as to seem to place real faith in them. Such people do not escape a light fault of frivolity, rashness, and idle curiosity — not, indeed, for consulting such pamphlets as such, but for their excess and overcredulity.

II. The other astrology is judicial — whereby men divine, from the motion of the stars, the aspect of the planets, and the course of the heavenly bodies, certain future things that are contingent, occurring by chance, or depending solely on human will and choice. Theologians teach that this too is twofold. One is that whereby, from the aspects of the stars, the fertility or barrenness of the earth, the diseases and deaths of animals and men, are foretold — not with certainty, but only as probable; and this is not superstitious, provided these future things are foretold only as probable. The second is called genethlialogy, whereby dignities, ranks, the beauty or ugliness of one's future spouse, are foretold for individuals. The third is that of elections, whereby it is divined, in every undertaking, what is to be done, what omitted, when one should leave the house, so that fortunate outcomes may follow. The fourth is that of fabricated images, whereby astrologers construct figures, numbers, and characters, which they combine, by a supposed mutual sympathy, with figures they claim to find in the heavens; and from this combination they foretell fortuitous events. St. Thomas treats all these matters at length (II-II, q. 96, art. 2), which the reader may consult.

III. All persons of sound mind hold these last three practices to be forbidden — indeed, altogether disparate from reality — since heavenly bodies have no power whatsoever over the human will, which is spiritual, whose free acts, whether honorable or harmful, meritorious or blameworthy, can in no way be traced back to bodily causes. For celestial bodies neither influence the will by their natural power (which would violate freedom, since such influence would be necessary), nor can they serve as signs — since there is no connection whatsoever between such altogether disparate things that would allow them to concur in producing these effects. The Angelic Doctor teaches all this (II-II, q. 95, art. 3). And, setting aside the many prohibitions of Sacred Scripture against this astrology, let it suffice to cite the words of the constitution of Sixtus V, issued in the year 1586, beginning "Coeli et terrae Creator Deus" ["God, Creator of Heaven and Earth"], where, among other things, it is stated: "We ordain and command that... those who presume to affirm that anything will come to pass concerning nativities and the dependent judgments of men — even if they do not claim to affirm this with certainty, but merely assert or hold it as probable — concerning contingent events, successes, and chance occurrences, or actions proceeding from human free will, are to act and proceed against, and to punish more severely, in accordance with the canonical penalties." The objections astrologers commonly raise are too frivolous to merit a refutation.

IV. Question I. Is it superstitious to divine free future events, not with certainty, but probably? Response: The affirmative opinion is common and true. The reason is that a probable assent is a determinate one, even though it admits some fear of the opposite. But no determinate influence of the stars upon the will can be given, even probably. Therefore even a merely probable foreknowledge of future things from the stars is superstitious. Wherefore, whether astrologers foretell free future events with certainty or with probability, they are always superstitious, since there is no connection whatsoever between the stars and human freedom.

V. Question II. Is a prediction that is merely conjectural free of superstition? Response: Fr. Castropalao (tract. 17, disp. 1, punct. 4, n. 8) teaches the affirmative, citing Vázquez and De Lugo in support; he seeks to prove this, first, on the grounds that Sixtus V did not prohibit this merely conjectural and slight prediction, since the Pontiff only forbade that foreknowledge of the future which had already been forbidden by divine and canon law, as is gathered from the preamble of the constitution. Secondly, he adds that this conjectural and doubtful prediction of a contingent future event is not an absolute prediction, but only a prediction resting on some rather slight conjecture — which is more a prediction of a contingency than of an effect.

VI. Against this opinion one could object that in the Sixtine constitution prediction is forbidden even if they do not assert or profess it as certain. Therefore even conjectural foreknowledge seems to be forbidden. What of the fact that this conjectural divination is as pernicious to the commonwealth and to divine worship as the probable kind? Indeed it is scarcely distinguished from it, except by a greater or lesser degree of probability. For if the lawful use of that conjectural divination were admitted, men inclined to the knowledge of hidden things would devote themselves to this vain science as though it were certain; since they would flatter themselves that they could advance beyond conjectures, and approach the bounds of probability, and from these reach the summit of certainty: and so under this most slender veil of conjectural prediction the crime of superstitious divination would be hidden and fostered. What of the fact that Castropalao himself concedes that such diviners are to be punished in the external forum? Why should they be punished, if once any prediction of contingent future things from the stars were lawful? Indeed scarcely anyone could be punished, the opinion of Castropalao once admitted: for anyone could excuse himself under the pretext of a conjectural prediction. Therefore Pope Sixtus, as we have seen, forbids divination whether certain or conjectural: which conjectural prediction has always been forbidden both by divine and by natural law, for the reasons alleged.

VII. These objections I have raised, however, are not so pressing as to render Castropalao's opinion false in every sense. For St. Thomas teaches that astrologers can, in general, conjecturally predict wars and other chance events — because heavenly bodies, though they do not act upon the intellect and the will, do nevertheless influence the passions; and since few people resist these, astrologers can in general conjecture certain future events, though not with respect to this or that particular case. For the Angelic Doctor says (II-II, q. 95, art. 5, ad 3): "The greater part of men follow their passions, which are movements of the sensitive appetite, to which celestial bodies can indeed contribute; but there are few wise men who resist such passions. And so astrologers can, for the most part, predict truly, especially in general matters, though not in particular ones — since nothing prevents some individual man from resisting his passions by free choice. Whence astrologers themselves say that the wise man will rule the stars, insofar, that is, as he rules his own passions." If, therefore, one considers the nature of these things — namely, celestial bodies, and bodily or sensory passions — a connection does exist between them, since the former really do influence the latter; and although all men can master their passions, few in fact do so; hence, if this is what is considered, astrologers can conjecturally foretell, from the common influence of the stars upon bodily appetites, various general movements of the passions. But nothing regarding matters that depend on free choice can they foretell with any certainty in particular cases — since any given man can, by conjectural reasoning, resist several bodily impulses of appetite. Indeed, not even the common prediction of astrologers, which alone can be lawful, is worth attending to, but rather to be wholly disregarded — for although astrologers might, from the motion, aspect, and position of the stars, and their influence upon the passions, be able to divine something, since this can nonetheless be impeded and the passions restrained by countless accidental circumstances, all such divination — whether general or particular, probable or conjectural — with respect to matters depending on free choice, is altogether to be despised, as Jeremiah says (ch. 10): "Be not afraid of the signs of heaven, which the heathens fear; for the laws of the people are vain."

VIII. Question III. Are astrologers permitted to predict a person's temperament, inclination, and bodily characteristics from the sign of their nativity? Response: Theologians dispute much on this point; I will settle the matter briefly. It is established from what has been said that astrologers cannot, in any way — whether probably or conjecturally — predict free future events. Moreover, that astrologers cannot certainly predict an infant's temperament and inclinations from the horoscope of its nativity is likewise clear. For the exceedingly rapid motion of the heavens, the aspects of the stars, their retrogradations and oppositions, escape the grasp of the mind, as even the most expert mathematicians themselves admit. It should be added that the precise moment of nativity is exceedingly difficult to determine, on account of the exceedingly rapid revolution of the heavens. What, moreover, of the fact that the influences of the heavens at the time of conception contribute more to temperament and human inclinations than those at the time of birth? And this moment is altogether unknown to astrologers. Finally, men's temperaments are changed by diet, by upbringing, and by very many other factors. All these considerations, taken together — along with many others I pass over — prevent astrologers from being able even probably to predict children's temperaments and inclinations.

IX. Having shown the uselessness of astrologers' divination, it remains to say whether such divination is superstitious. It has been established above that natural astrology is lawful with respect to those events which necessarily follow from the motion and aspect of the stars. But that astrology which divines a person's future constitution, temperament, and inclination from the horoscope of their nativity, we hold — and maintain — to be unlawful. The theologians of Salamanca cite Trullench, who asserts that this divination is by its very nature unfit, and a mortal sin; they themselves, however, with Suárez, Layman, Fagundez, and Tamburini, deny this, saying that by its very kind it is only a falsehood and a rash error, not superstition. Now to lie in the abstract is not a mortal sin, but only venial. It will therefore be only a venial fault, against prudence and truth, to divine a future temperament from the horoscope of a nativity. They add (loc. cit., n. 43) that this divination is lawful, provided the astrologer predicts future inclinations only probably and conjecturally. But once it is granted that there exist no grounds at all upon which a probable judgment about a future temperament and inclination could be formed, it follows immediately that this divination is altogether useless and false — as the aforesaid theologians themselves readily admit. Now if such divination is useless and false, I do not see why it should be called free of superstition.

Whether it is afterward always a mortal sin, I would not venture to decide. As for practice, Christians are to be advised to abstain from seeking such divinations, and from listening to such astrologers who whisper their falsehoods and fables through tubes into the ears of the ignorant and foolish in public squares, and thereby extract their money. For although they profess with their mouths to place no faith in such things, their actions indicate the contrary: for it is hard to believe that they would spend their money merely out of curiosity to hear things they themselves regard as fables. Let them, then, keep their money, and mock this most ignorant and worthless breed of men, wholly ignorant of letters and of the astrological art.

X. Those who consult astrologers to reveal to them some hidden crime — a theft, a murder, or other crimes, whether committed or merely alleged — sin most gravely, because such things cannot be discovered without the art of a demon; and thus those who consult them induce astrologers to practice superstition. What, moreover, of the fact that it is not even lawful to induce a man who truly knows of an altogether hidden crime to reveal it, bypassing the due order of justice?

XI. Question IV. Is it lawful to ask that hidden treasures, underground waters, or corpses hidden beneath tombstones be revealed by those who boast of knowledge of such things? Response: That waters flowing within the veins of the earth can be discerned by natural signs — vapors, and other emanations given off — no one denies. Metals too, present in mines, can be discerned by natural power through several signs, chiefly from the character of the plants that tend to grow there. The knowledge of both, then, can be sought without superstition, since knowledge of either can be obtained without the fault of superstition. But treasures, or corpses hidden beneath tombstones, cannot be discovered without a pact with a demon. Those, therefore, who demand that these be revealed sin gravely, since they induce diviners to commit superstition. What deep roots of folly are these! If God, in his providence, rarely permits a demon to reveal such things, it is so that the endless evils which wicked men are accustomed to perpetrate, once furnished with an abundance of riches, might be prevented. What, then, if others were disappointed of their hope of treasure?

XII. Question V. Are diviners bound to restore the price received for their divination? The singular opinion of Fr. Sánchez is here refuted. Response: When diviners foretell things that escape natural knowledge — as when they predict things that depend solely on free will — they are bound to restore the price received for such prediction, because those who received it were unjustly deceived by such impostures; and if others were led by them into this same practice through foolish credulity in such deceptions, they must compensate the resulting damages, since they were the cause of the loss.

XIII. Fr. Thomas Sánchez (Bk. II, On Decalogue, ch. 38, n. 36) holds a singular opinion on this matter. Lest I seem to misrepresent him, I transcribe his own words. He says: "If we speak of the price received for rendering this judgment, Gratian (ch. Qui habetis, 14, q. 1) teaches that it must be restored to the poor as base gain. But a distinction must be drawn here. If that astrologer employed no effort at all, and knew, by the diabolical art, what could be known by no other means, then — whether or not the predicted effect came to pass — he is bound to restore the price to the giver, since he applied no diligence of his own, but the effect happened by chance, or did not happen. But money is given on account of the labor expended by him, labor useful for achieving the effect — just as, if someone entirely ignorant of medicine applied useless remedies to a sick person, he would be bound to restore the price of the cure to the patient, even if the patient happened by chance to recover from the illness. And although the one who consulted the astrologer erred in this, offering a price for a shameful thing, the truer opinion holds that the price must be restored to him, until he is condemned by a judicial sentence to forfeit it. But if that astrologer, or diviner, applied his own effort, and BY THE ART OF THE DEVIL... he is not bound to restore the price received, because the thing so happened; for he applied his own effort, however base, and it is not subject to restitution according to the truer opinion." Manuel (Bk. 1 of the Summa, 1st edition, ch. 7, n. 4), and Salas (Bk. 3, q. 12, art. 5, tract. 5, disp. 22, sect. 8, n. 79 at the end) teach the same. Navarro (ibid., n. 163–164) adds that the price must be restored without distinction, when the thing does not turn out as predicted. But this I do not believe, when he himself applied the diligence necessary for that effect through the art of the devil: just as a physician who treats a patient according to the rules of his art is not bound to restore the price to a patient who dies, since the diligence applied by that sorcerer [N.B.] is to be valued at a price. Nor in this case is he bound to compensate for damages and expenses to the one who consulted him; but [he is bound] when he applies no effort at all, or is himself ignorant of the DIABOLICAL art.

XIV. Is the diabolical art, then, to be valued at a price? If diviners have no dealings whatsoever with the devil, they are bound to restore the price received for divination, whether or not the effect occurs — because in that case they are ignorant of the divinatory art, and deceive their clients, to whom they render no effort at all, and undergo no trouble in learning the secrets of their supposed art. On the contrary — if they consult the devil, and learn the secrets of the art from so great a master, then, as skilled practitioners of the divinatory art, they are free of the obligation of restitution, and may lawfully keep the price received, whether or not the predicted effect follows — just as a physician who treats a patient according to the rules of his art is not bound to restore the price received, whether the patient recovers or dies. This seems to me a monstrous paradox, repugnant to common sense. In the end, an opinion has been devised that teaches that dealing with the devil can be useful and profitable, and that the profit acquired from such diabolical commerce may be retained. What an erroneous fabrication!