Thus far as to express divination, or invocation of the devil, which is detestable; and the very consulting of persons that use such unlawful means is, according to the judgment of all casuists, the high road to eternal damnation.
Now as to tacit divination, or invocation of the devil, that is divided into two subaltern kinds. The first kind is, when for the sake of knowing hidden things, they make use of a vain and superstitious disposition existing in things to judge from; which disposition is not of a sufficient virtue to lead them to any real judgment. The second kind of tacit divination is, when that knowledge is sought by the disposition of those things which men effect on purpose and of their own accord, in order to come by and acquire that knowledge.
Both these kinds of tacit divination are again subdivided into several species, as are particularly mentioned by St. Thomas, Secundâ Secundæ, Quæst. 95, Art. 3; Gregory de Valentine, tom. iii. Disput. 6. Quæst. 12. Puncto 2; Toletus, in Summa. lib. iv. cap. 15; and Michael Medina, lib. ii. de Recta in Deum fide: post Sanctum Augustinum. lib. ii. de Doct. Christ. cap. 19. et seq.
The first of these kinds of tacit divination contains under it the following several species:—
The first species is called Genethliacal, which is when from the movement or situation of the stars, men's nativities are calculated and inquired into so far, as that from such a search they pretend to deduce the knowledge of human effects, and the contingent events that are to attend them. This Thomas Aquinas and Sixtus Quintus condemns; but I shall, with humility and submission to greater judgments, inquire hereafter into their reasons, and give my opinion why I think this no evil art; but I submit my opinion, if, after it is given, it is thought erroneous.
The second is augury, when anything is predicted from the chattering of birds, or the voice of animals, and this may be either lawful or unlawful. If it comes from natural instinct, for brutes having only a sensitive soul, have their organs subject to the disposition of the greater bodies in which they are contained, and principally of all to the celestial bodies, his augury is not amiss. For if when crows are remarked to caw, as the vulgar phrase is, more than ordinary, it is, judging according to the instinct of their nature, if we expect rain, and we may reasonably depend upon it, we shall be right if we foretell rain to be at hand. But sometimes the devils actuate those brute animals to excite vain ideas in men, contrary to what the instinct of their nature compels them to. This is superstitious and unlawful, and forbid in holy writ.
The third is aruspicy, when from the flight of birds, or any other motion of any animals whatsoever, persons pretend to have an insight and a penetrative knowledge into occult and hidden matters.
The fourth consists in omens, when, for example, a man from any words which others may have spoken on purpose, or by accident, pretends to gather a way of looking into and knowing anything of futurity.
The fifth is chiromancy, which consists in making a pretence to the knowledge of future things by the figures and the lines of the hands; and if it be by consulting the shoulder-bones of any beast, it goes by the name of spatulamancy.