Teaching Christianity (continued)
one must condemn a superstitious use of signs.
Though where no use is made of spells and invocations and "characters," [102] it is often doubtful whether the thing that is tied, or otherwise attached to the body, as a cure, works by force of nature, in which case it may be freely employed; or whether its effect comes from the significant symbolism of tying it on, in which case Christians should be all the more prudently on their guard against it, the more effectively it seems to work.[103] But when it is impossible to tell by what cause any such thing works effectively, what makes the difference is the spirit in which people make use of it, at least in the curing of bodies or mixing of ingredients, whether for medicinal or agricultural purposes.
46. Coming now to knowledge of the stars, this is not a matter for narrative but for description, and scripture has very little to say about it. But while most people know about the phases of the moon, which even govern the solemn annual celebration of the Lord's passion, very few indeed know anything with any certainty about the rising or the setting or the other movements of the rest of the firmament. Such knowledge of itself, while not involving people in superstition, is nevertheless of little, indeed practically no help at all in expounding the divine scriptures; in fact, unprofitable absorption in it is more of a hindrance than a help, and because it is so closely related to that most baleful error of those who chant the fatuous follies of Fates,[104] the most appropriate and correct thing to do is to ignore it. But besides its description of present realities, it also has this in common with the narrative of past events, that from the present positions and movements of the stars it is able according to its proper rules to trace their courses in the past.
According to the same rules it can also make predictions about their future courses, which are neither mere guesswork nor a taking of omens, but rationally calculated and certain; not that we should attempt to draw any conclusions from them about our own fates[105] and future experiences, like the ravings of the genethliacs,[106] but only about the stars themselves. Thus in the same way as the observer of the moon can tell us, from his observation of what phase it is in today, both what phase it was in however many years you like previously, and what phase it will be in in however many years you like in the future, so too about any one of the stars, those who are learned in observing them and making the necessary calculations have habitually been able to give correct answers. About this whole branch of knowledge I have candidly said what I think, as far as the use made of it is concerned.
30, 47. Other arts and crafts too use their experience of the past to make conjectures about the future, such as those by which things are made that remain after the craftsman has done his work, like houses and benches and pots and other things like that; or those which cooperate with God as he works in the world, such as medicine and agriculture and seamanship, or those whose whole effect consists in the action, such as dancing and racing and wrestling. Clearly, none of the practitioners of any of these arts and crafts moves hand or foot in practicing them without combining memory of the past with what is expected in the future.
However, only a slight and cursory knowledge of these matters needs to be acquired in the course of this life—not of course for the practice of them, unless some duty should oblige us to it, which is not what we are dealing with at the moment, but for making an intelligent judgment, in case we should altogether fail to see what scripture is intending to suggest, when it brings in some figurative expressions from these arts and crafts.
31, 48. There remain those matters that belong not to the senses of the body but to the rational mind, where the disciplines of rational discourse and of mathematics hold sway. The discipline of rational discourse, indeed, is of the