Aquinas on Astrology

[Treacy17]

Can someone explain to me Aquinas’ view on astrology in Prima Pars Q115? It seems that, while he says that the human will trumps all, the stars and planets do have an effect on our passions/bodies, which doesn’t make sense to me.

 

[Inbonum]

Please cite confusing parts.

 

[Treacy17]

From Article 3: “Since every multitude proceeds from unity; and since what is immovable is always in the same way of being, whereas what is moved has many ways of being: it must be observed that throughout the whole of nature, all movement proceeds from the immovable. Therefore the more immovable certain things are, the more are they the cause of those things which are most movable. Now the heavenly bodies are of all bodies the most immovable, for they are not moved save locally. Therefore the movements of bodies here below, which are various and multiform, must be referred to the movement of the heavenly bodies, as to their cause.”
Article 4: “The heavenly bodies can directly and of themselves act on bodies, as stated above (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.”

I understand that in article 4, he’s claiming that while the heavenly bodies have an effect on our bodies and passions, our will can overcome them. What confuses me is how he comes to the conclusion that the heavenly bodies have an effect on our bodies and passions

 

[Wesrock]

This to a large degree follows what I understand of Aristotlean cosmology (and ancient Hellenistic cosmology in general), in which the universe is modeled as a number of concentric spheres with the Earth at the center. You might liken it to a complex machine in which the movement of outermost spheres give movement to the spheres beneath them, and so on down the chain, with the least mutable bodies in the uppermost spheres, and the more mutable bodies in the lower ones. The heavenly bodies in general were considered to only change (move) in their local motion. Otherwise they did not change at all. The general belief was that this ordering could affect the ordering of things on Earth, and in animals it could affect the sensitive appetites, though not cause anything in a necessary way even in lower animals.

The observation that the sun was necessary for life (a more obvious example they used) was for the most part correct for the world as it was.

Anyway, St. Thomas’ writings cover many things. Metaphysics (first principles), physics, logic, theology, sacraments, scripture. Contrary to what some will say, he did not believe in armchair philosophy. He did believe in the importance of empirical observation and measurements and all that. He cites measurements for ththe size of the sun (they overestimated its size, but their method wasn’t terrible given what they had available) and the circumference of the Earth (some of the figures he was aware of were more accurate than others). Their empirical tools were rather limited, then, and there was general belief from some observation that people were affected (but not controlled) by such things. If he were alive today it’s a sure bet he’d revise his general physics and cosmology. What continues to be relevant does require separating out some topics.

 

[Inbonum]

Moon is heavenly body which has influence on human body, Sun also, stars…
There is couple main things he talks about.
Here he says that heavenly bodies can have influence on senses of body but accidentally

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.

He goes by analogy “if first would be correct then second would be, and third etc.” like this and concludes that as wrong:

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. All of which is manifestly false, and contrary to human habit.

And then here he spokes about body senses:

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.

And then he explains why heavenly bodies do not have significant influence on will, they have more influence on senses which give images to intellect and which is why intellect is affected by heavenly bodies.
He also says that intellect can be disordered if senses are disordered/disturbed and they give disordered “image” to intellect:

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.

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

This means that influence of heavenly bodies is less on will than on body senses- which are: sight, smell, taste etc.
Actually Aquinas with this refuted wrong beliefs of astrology which teaches that heavenly bodies have complete influence on human in way that humans don’t have free will.

 

[Wesrock]

Actually Aquinas with this refuted wrong beliefs of astrology which teaches that heavenly bodies have complete influence on human in way that humans don’t have free will.

Agreed. Compared to the popular beliefs of many of his time, his opinion largely minimized the impact astrology on persons.

 

[Inbonum]

@Wesrock And some of those false teachings of our time st. Thomas beats great.

 

[Treacy17]

I understand what he’s talking about with the will not being totally subject to the senses, but where I’m getting hung up is where he says that the heavenly bodies influence the senses. That part seems totally contrary to today’s scientific understanding (and if I’m understanding @Wesrock correctly, if he lived today he would agree more with today’s science).

 

[Wesrock]

That part seems totally contrary to today’s scientific understanding (and if I’m understanding @Wesrock correctly, if he lived today he would agree more with today’s science).

Yes, it is contrary to modern understanding and I think St. Thomas wouldn’t believe such things if he had the knowledge we do today.

 

[Inbonum]

But they influence senses in exact form that Aquinas wrote. You see Moon and eye “received” Moon through sense of sight. Moon influenced eye to see it. I would say that he described biology in form of philosophy to explain false teachings of astrology.

 

[Treacy17]

So if I’m understanding you correctly, you are saying that the influence Aquinas claimed the heavenly bodies have on our bodies is limited to the light that reflects off of them and allows us to see them.

 

[Inbonum]

@Treacy17 It is not limited to light. Sun heats body and you feel it through sense of touch.
You see stars and think how beautiful they are-your intellect is influenced by what you noticed with your sense.
Moon has gravity and it cause ebb tide and high tide to happen, it influences people and make them to feel different because of that change, to feel fear etc. or to move on other place to live so yes it has influence and it is not limited to light.
It is not what heavenly bodies are, it is about how they influence on us through our senses in many forms.
If you would be blind your sense of sight would be defect by Aquinas and heavenly bodies wouldn’t influence on you through your sense of sight to see them for example.