Chapter VII — On divination by augury, omens, and other such observations of external things

I. St. Thomas treats this question (II-II, q. 95, art. 7). "Augury" is commonly understood in reference to the chattering of birds. It is threefold. When future things are foretold from the flight, song, and number of the chattering, it is called, absolutely, augury. If this prediction is made from the flight, feeding, cry, or movements of birds, it is called auspice. If, however, the divination is made from the entrails, organs, or innards of birds sacrificed or slaughtered, it is then called haruspicy. When, however, divination is made from words uttered by men without any intention regarding the future, it is called an omen. Marcus Tullius writes much on this art in his books on divination, and praises the Etruscans as most skilled in it, whom he says the Romans often summoned to instruct them. I could transcribe much more from this source for erudition's sake; but I think it better to touch only briefly upon those points that pertain to the formation of our own moral conduct.

II. Question I. Is it lawful to foretell the future from the song, flight, or cry of birds? Response: If the discussion concerns certain future effects that depend on natural causes — such as rains, storms, droughts, and the like — it is lawful to conjecture such things from the song, flight, and movement of birds, since these are natural signs of such effects. For the senses of these animals are more strongly affected than those of men by changes in the air and the influences of the stars; and for this reason these creatures are accustomed either to sing or to fly more swiftly when such changes in the weather are impending. There is, then, no superstition, but a prudent observation, in gathering from the song, chattering, and flight of birds indications of rain, fair weather, and storms. The Angelic Doctor explains all this (loc. cit.): "The cause of the actions of brute animals is their instinct, by which they are moved, in a certain natural manner: for they do not have dominion over their own acts. This instinct, however, can proceed from a twofold cause. In one way, from a bodily cause: for since brute animals have only a sensitive soul, all their acts must be the acts of bodily organs, and consequently of animal bodies, and primarily of celestial bodies. And so nothing prevents some of their operations from being signs of future things, insofar as they conform themselves to the dispositions of the celestial bodies and of the surrounding air, from which certain future events arise." Hence it is, adds the Angelic Doctor, that when the crow caws frequently, it indicates coming rain; other creatures give similar signs foretelling such effects.

III. Manifest superstition, however, is committed when one attempts to foretell free future contingent events from the aforesaid signs of birds or other animals. The reason has already been given several times: namely, that free future events depend on the will. Hence God commands (Deut. 18): "Let there not be found among you one who observes auguries." Certain scriptural authorities that are commonly cited in opposition are interpreted by St. Thomas (loc. cit.) — as when Joseph said (unaware [of the true reason]): "Do you not know that there is no one like me in the science of augury?" — Augustine likewise teaches that this was said by Joseph merely as a pretext.

IV. Question II. Is it lawful to foretell future things from words uttered by chance, or from fortuitous events? Response: The negative conclusion is certain and common. For human words uttered by chance are signs at will, having no relation to, and no influence upon, any future thing whatsoever. It is therefore in no way lawful to predict anything from such a chance utterance of words. That Eliezer observed the girl's words, and [that St. Thomas cites] the case of Gideon (loc. cit., ad 3), is to be explained by a special revelation from God, as Augustine also teaches. Similar observations, then, are tainted with superstition: as, for instance, interpreting it unfavorably if alms are requested on the first day of the week; if a dog or cat crosses one's path first thing in the morning; if one sneezes in the morning; if one's clothes are gnawed by mice; if one bumps one's head against a doorway; and six hundred other similar observances, handed down from the pagans to ignorant and unlearned Christians. For because something sad or unlucky sometimes happens by chance after similar signs, men, prone to superstition and deceived by a demon, immediately establish such signs as ill omens.

V. Question III. Is it superstitious to foretell the future from parts of the human body? Response: There are three principal parts of the body commonly observed in divination: the hands, the head, and the feet. Divination whereby a person's future is predicted from the lines of the hands is called chiromancy; that whereby something is foretold from the lines of the feet is called podomancy; that which conjectures from the lines of the forehead and the character of the face is called metoposcopy; and that, finally, which draws auguries from the whole body and its members, is called physiognomy. Each of these is twofold: one natural, the other astrological. The astrological kind predicts free and altogether contingent future events from the features of the members; the natural kind, on the other hand, conjectures health, temperament, and disease from the body's disposition and the size of the hand. With these preliminaries noted, we say...

[Physiognomy, which conjectures from the body's habitual bearing the signs of weakness, courage, strength, or timidity, is lawful — as Ecclesiasticus 19 says: "A man is known by his look, and a man of understanding, when thou meetest him, is known by his countenance. A man's attire, and excessive laughter, and gait, shew what he is." Just as the strength, agility, and speed for racing of other animals — horses, oxen, and the like — are gathered from the excellent disposition of their bodies, so too men's natural inclinations, temperaments, and the like are discerned from the variety of their features and other bodily members. And this no one doubts to be lawful. But to divine, by astrological physiognomy, future contingent, chance, and free events is superstitious, as all agree, for the reason so often given: namely, that the body's disposition and that of its members has no influence at all upon future contingent and free events, which depend on the will alone. What has been said of physiognomy is likewise to be said of natural and astrological chiromancy, and of the other two. Though what authors commonly teach concerning the lines of the hands I consider a fabrication, from which I think no probable conjecture at all can be drawn regarding natural inclinations, or a longer or shorter lifespan.]

VI. Question IV. Do the Egyptians — those called by the common name of Gypsies — sin gravely by predicting good or bad fortune from the lines of the hand? Response: If they do this seriously, they undoubtedly sin mortally: for, as we have often said, this is a species of superstition, since no natural cause can be assigned that could produce such effects. If it is done merely for amusement, the more probable authors teach that only a venial sin of curiosity is committed. But in practice this is scarcely done without grave fault, both on account of the scandal involved, and on account of the credulity that people — women especially — place in such charlatans. All, therefore, ought to be urged to abstain altogether from consulting them. For while such fortune-tellers ply their predictions, they support a wicked art, and provide wicked men the occasion to sin.