The Refutation of All Heresies

For this reason it is impossible to fix the horoscope from the (period of) conception. But neither can this be done from (that of) birth. For, in the first place, there exists the difficulty as to when it can be declared that there is a birth; whether it is when the foetus begins to incline towards the orifice, or when it may project a little, or when it may be borne to the ground. Neither is it in each of these cases possible to comprehend the precise moment of parturition, or to define the time. For also on account of disposition of soul, and on account of suitableness of body, and on account of choice of the parts, and on account of experience in the midwife, and other endless causes, the time is not the same at which the foetus inclines towards the orifice, when the membranes are ruptured, or when it projects a little, or is deposited on the ground; but the period is different in the case of different individuals. And when the Chaldeans are not able definitely and accurately to calculate this, they will fail, as they ought, to determine the period of emergence.

That, then, the Chaldeans profess to be acquainted with the horoscope at the periods of birth, but in reality do not know it, is evident from these considerations. But that neither is their horoscope infallible, it is easy to conclude. For when they allege that the person sitting beside the woman in travail at the time of parturition gives, by striking a metallic rim, a sign to the Chaldean, who from an elevated place is contemplating the stars, and he, looking towards heaven, marks down the rising zodiacal sign; in the first place, we shall prove to them, that when parturition happens indefinitely, as we have shown a little before, neither is it easy to signify this (birth) by striking the metallic rim. However, grant that the birth is comprehensible, yet neither is it possible to signify this at the exact time; for as the noise of the metallic plate is capable of being divided by a longer time and one protracted, in reference to perception, it happens that the sound is carried to the height (with proportionate delay). And the following proof may be observed in the case of those felling timber at a distance. For a sufficiently long time after the descent of the axe, the sound of the stroke is heard, so that it takes a longer time to reach the listener. And for this reason, therefore, it is not possible for the Chaldeans accurately to take the time of the rising zodiacal sign, and consequently the time when one can make the horoscope with truth. And not only does more time seem to elapse after parturition, when he who is sitting beside the woman in labour strikes the metallic plate, and next after the sound reaches the listener, that is, the person who has gone up to the elevated position; but also, while he is glancing around and looking to ascertain in which of the zodiacal signs is the moon, and in which appears each of the rest of the stars, it necessarily follows that there is a different position in regard of the stars, the motion of the pole whiffing them on with incalculable velocity, before what is seen in the heavens is carefully adjusted to the moment when the person is born.