1 Objection 1: It would seem that the heavenly bodies are the cause of human actions. For since the heavenly bodies are moved by spiritual substances, as stated above Question 110, Article 3), they act by virtue thereof as their instruments. But those spiritual substances are superior to our souls. Therefore it seems that they can cause impressions on our souls, and thereby cause human actions.
1 Ad quartum sic proceditur. Videtur quod corpora caelestia sint causa humanorum actuum. Corpora enim caelestia, cum moveantur a spiritualibus substantiis, sicut supra dictum est, agunt in virtute earum quasi instrumenta. Sed illae substantiae spirituales sunt superiores animabus nostris. Ergo videtur quod possint imprimere in animas nostras, et sic causare actus humanos.
2 Objection 2: Further, every multiform is reducible to a uniform principle. But human actions are various and multiform. Therefore it seems that they are reducible to the uniform movements of heavenly bodies, as to their principles.
2 Praeterea, omne multiforme reducitur in aliquod uniforme principium. Sed actus humani sunt varii et multiformes. Ergo videtur quod reducantur in uniformes motus caelestium corporum, sicut in sua principia.
3 Objection 3: Further, astrologers often foretell the truth concerning the outcome of wars, and other human actions, of which the intellect and will are the principles. But they could not do this by means of the heavenly bodies, unless these were the cause of human actions. Therefore the heavenly bodies are the cause of human actions.
3 Praeterea, astrologi frequenter vera annuntiant de eventibus bellorum, et aliis humanis actibus, quorum principia sunt intellectus et voluntas. Quod facere non possent secundum caelestia corpora, nisi essent humanorum actuum causa. Sunt ergo corpora caelestia humanorum actuum causa.
4 On the contrary, Damascene says De Fide Orth. ii, 7) that the heavenly bodies are by no means the cause of human actions.
4 Sed contra est quod Damascenus dicit, quod corpora caelestia humanorum actuum nequaquam sunt causa.
5 I answer that, The heavenly bodies can directly and of themselves act on bodies, as stated above Article 3). They can act directly indeed on those powers of the soul which are the acts of corporeal organs, but accidentally: because the acts of such powers must needs be hindered by obstacles in the organs; thus an eye when disturbed cannot see well. Wherefore if the intellect and will were powers affixed to corporeal organs, as some maintained, holding that intellect does not differ from sense; it would follow of necessity that the heavenly bodies are the cause of human choice and action.
It would also follow that man is led by natural instinct to his actions, just as other animals, in which there are powers other than those which are affixed to corporeal organs: for whatever is done here below in virtue of the action of heavenly bodies, is done naturally. It would therefore follow that man has no free-will, and that he would have determinate actions, like other natural things. All of which is manifestly false, and contrary to human habit.
It must be observed, however, that indirectly and accidentally, the impressions of heavenly bodies can reach the intellect and will, forasmuch, namely, as both intellect and will receive something from the inferior powers which are affixed to corporeal organs. But in this the intellect and will are differently situated. For the intellect, of necessity, receives from the inferior apprehensive powers: wherefore if the imaginative, cogitative, or memorative powers be disturbed, the action of the intellect is, of necessity, disturbed also.
The will, on the contrary, does not, of necessity, follow the inclination of the inferior appetite; for although the passions in the irascible and concupiscible have a certain force in inclining the will; nevertheless the will retains the power of following the passions or repressing them. Therefore the impressions of the heavenly bodies, by virtue of which the inferior powers can be changed, has less influence on the will, which is the proximate cause of human actions, than on the intellect.
To maintain therefore that heavenly bodies are the cause of human actions is proper to those who hold that intellect does not differ from sense. Wherefore some of these said that such is the will of men, as is the day which the father of men and of gods brings on Odyssey xviii 135). Since, therefore, it is manifest that intellect and will are not acts of corporeal organs, it is impossible that heavenly bodies be the cause of human actions.
5 Respondeo dicendum quod corpora caelestia in corpora quidem imprimunt directe et per se, sicut iam dictum est. In vires autem animae quae sunt actus organorum corporeorum, directe quidem, sed per accidens, quia necesse est huiusmodi actus harum potentiarum impediri secundum impedimenta organorum, sicut oculus turbatus non bene videt. Unde si intellectus et voluntas essent vires corporeis organis alligatae, sicut posuerunt aliqui, dicentes quod intellectus non differt a sensu; ex necessitate sequeretur quod corpora caelestia essent causa electionum et actuum humanorum.
Et ex hoc sequeretur quod homo naturali instinctu ageretur ad suas actiones, sicut cetera animalia, in quibus non sunt nisi vires animae corporeis organis alligatae, nam illud quod fit in istis inferioribus ex impressione corporum caelestium, naturaliter agitur. Et ita sequeretur quod homo non esset liberi arbitrii, sed haberet actiones determinatas, sicut et ceterae res naturales. Quae manifeste sunt falsa, et conversationi humanae contraria. Sciendum est tamen quod indirecte et per accidens impressiones corporum caelestium ad intellectum et voluntatem pertingere possunt; inquantum scilicet tam intellectus quam voluntas aliquo modo ab inferioribus viribus accipiunt, quae organis corporeis alligantur.
Sed circa hoc diversimode se habent intellectus et voluntas. Nam intellectus ex necessitate accipit ab inferioribus viribus apprehensivis, unde turbata vi imaginativa vel cogitativa vel memorativa, ex necessitate turbatur actio intellectus. Sed voluntas non ex necessitate sequitur inclinationem appetitus inferioris, licet enim passiones quae sunt in irascibili et concupiscibili, habeant quandam vim ad inclinandam voluntatem; tamen in potestate voluntatis remanet sequi passiones, vel eas refutare. Et ideo impressio caelestium corporum, secundum quam immutari possunt inferiores vires, minus pertingit ad voluntatem, quae est proxima causa humanorum actuum, quam ad intellectum.
Ponere igitur caelestia corpora esse causam humanorum actuum, est proprium illorum qui dicunt intellectum non differre a sensu. Unde quidam eorum dicebant quod talis est voluntas in hominibus, qualem in diem inducit pater virorum deorumque. Quia ergo constat intellectum et voluntatem non esse actus organorum corporeorum, impossibile est quod corpora caelestia sint causa humanorum actuum.
6 Reply to Objection 1: The spiritual substances, that move the heavenly bodies, do indeed act on corporeal things by means of the heavenly bodies; but they act immediately on the human intellect by enlightening it. On the other hand, they cannot compel the will, as stated above Question 111, Article 2).
6 Ad primum ergo dicendum quod spirituales substantiae quae caelestia corpora movent, in corporalia quidem agunt mediantibus caelestibus corporibus, sed in intellectum humanum agunt immediate illuminando. Voluntatem autem immutare non possunt, ut supra habitum est.
7 Reply to Objection 2: Just as the multiformity of corporeal movements is reducible to the uniformity of the heavenly movement as to its cause: so the multiformity of actions proceeding from the intellect and the will is reduced to a uniform principle which is the Divine intellect and will.
7 Ad secundum dicendum quod, sicut multiformitas corporalium motuum reducitur sicut in causam in uniformitatem motuum caelestium; ita multiformitas actuum qui sunt ab intellectu et voluntate, reducitur in principium uniforme quod est intellectus et voluntas divina.
8 Reply to Objection 3: The majority of men follow their passions, which are movements of the sensitive appetite, in which movements of the heavenly bodies can cooperate: but few are wise enough to resist these passions. Consequently astrologers are able to foretell the truth in the majority of cases, especially in a general way. But not in particular cases; for nothing prevents man resisting his passions by his free-will. Wherefore the astrologers themselves are wont to say that the wise man is stronger than the stars, forasmuch as, to wit, he conquers his passions.
8 Ad tertium dicendum quod plures hominum sequuntur passiones, quae sunt motus sensitivi appetitus, ad quas cooperari possunt corpora caelestia, pauci autem sunt sapientes, qui huiusmodi passionibus resistant. Et ideo astrologi ut in pluribus vera possunt praedicere, et maxime in communi. Non autem in speciali, quia nihil prohibet aliquem hominem per liberum arbitrium passionibus resistere. Unde et ipsi astrologi dicunt quod sapiens homo dominatur astris, inquantum scilicet dominatur suis passionibus.