Thomas Aquinas, Compendium of Theology

Nevertheless we should not lose sight of the fact that the human intellect is indebted to the sense powers for the origin of its knowledge. This is why intellectual knowledge is thrown into confusion when the soul's faculties of phantasm, imagination, or memory are impaired. On the other hand, when these powers are in good order, intellectual apprehension becomes more efficient. Likewise, a modification in the sensitive appetite tends to bring about a change in the will, which is a rational appetite, as we know from the fact that the object of the will is the good as apprehended. According as we are variously disposed in the matter of concupiscence, anger, fear, and other passions, a thing will at different times appear to us as good or evil.

On the other hand, all the powers of the sensitive part of our soul, whether they are apprehensive or appetitive, are the acts of certain bodily organs. If these undergo modification, the faculties themselves must, indirectly, undergo some change. Therefore, since change in lower bodies is influenced by the movement of the heavens, the operations of the sensitive faculties are also subject to such movement, although only per accidens. And thus heavenly movement has some indirect influence on the activity of the human intellect and will, so far as the will may be inclined this way or that by the passions.

Nevertheless, since the will is not subject to the passions in such a way as necessarily to follow their enticement, but on the contrary has it in its power to repress passion by the judgment of reason, the human will is not subject to impressions emanating from heavenly bodies. It retains free judgment either to follow or to resist their attractions, as may seem to it expedient. Only the wise act thus; the masses follow the lead of bodily passions and urgings. For they are wanting in wisdom and virtue.