What IS the definition of "subtle" as Aquinas uses it?

[japhy]

I’ve been reading parts of the Summa, and I can’t find an adequate definition of what subtlty is. What does it mean for a body to be subtle? The closest he gets to defining it is in Q83, A1 (emphasis mine):

Subtlety takes its name from the power to penetrate. Hence it is said in De Gener. ii that “a subtle thing fills all the parts and the parts of parts.” Now that a body has the power of penetrating may happen through two causes. First, through smallness of quantity, especially in respect of depth and breadth, but not of length, because penetration regards depth, wherefore length is not an obstacle to penetration. Secondly, through paucity of matter, wherefore rarity is synonymous with subtlety: and since in rare bodies the form is more predominant over the matter, the term “subtlety” has been transferred to those bodies which are most perfectly subject to their form, and are most fully perfected thereby: thus we speak of subtlety in the sun and moon and like bodies, just as gold and similar things may be called subtle, when they are most perfectly complete in their specific being and power. And since incorporeal things lack quantity and matter, the term “subtlety” is applied to them, not only by reason of their substance, but also on account of their power. For just as a subtle thing is said to be penetrative, for the reason that it reaches to the inmost part of a thing, so is an intellect said to be subtle because it reaches to the insight of the intrinsic principles and the hidden natural properties of a thing. In like manner a person is said to have subtle sight, because he is able to perceive by sight things of the smallest size: and the same applies to the other senses. Accordingly people have differed by ascribing subtlety to the glorified bodies in different ways.

From Scripture, the best I could find was Wisdom 7:21-24:

I learned both what is secret and what is manifest, for wisdom, the fashioner of all things, taught me. For in her there is a spirit that is intelligent, holy, unique, manifold, subtle, mobile, clear, unpolluted, distinct, invulnerable, loving the good, keen, irresistible, beneficent, humane, steadfast, sure, free from anxiety, all-powerful, overseeing all, and penetrating through all spirits that are intelligent and pure and most subtle. For wisdom is more mobile than any motion; because of her pureness she pervades and penetrates all things.

But I don’t really know what it means. That is, what does it mean for our glorified bodies to be subtle? What does that imply? What manner of penetration is available to our glorified bodies? Can anyone help me out?

 

[Truthstalker]

He refers to De Gener.ii, which I think is Augustine’s work by that name.

Kreeft does not define subtlety in his Summa of the Summa, nor is the passage you refer to one he selected for his work. I would conclude that he didn’t think it all that signficant.

Did you look in the Catholic Encyclopedia on line?

I realize this probably doesn’t help at all, so my answer to your question is no. I cannot help you.

 

[japhy]

He refers to De Gener.ii, which I think is Augustine’s work by that name.

Yeah, I haven’t looked there yet. (Edit: De Gener is Aristotle’s work, not Augustine’s.)

Did you look in the Catholic Encyclopedia on line?

Yeah. Subtle is not in the (old) Catholic Encyclopedia, nor in an online Catholic Dictionary I found. Maybe it’s in the new Catholic Encyclopedia…

 

[JimG]

It sounds a little confusing to me, mainly because Aquinas here seems to be applying the concept to both material and non-material (incorporeal) beings. Non-material beings are spirit, and do not occupy space, so it would seem to me that the attribute of “subtlety” is for them a given.

With respect to material beings, I suppose it refers to the ability of Christ’s glorified body, for example, to pass through sold objects such as the walls of the upper room.

Aquinas was speaking philosophically, yet the idea can have an application in physical structure. At some point, modern physics regarded all matter as composed of very small particles–even zero dimension particles. In such a structure, there could in theory be plenty of “space” for two objects to pass through each other without in fact touching. I have read at least one science fiction story which used the concept.

It could also relate to the mind being able to control the body’s function in such fine detail as to make such interpenetration possible.

But those are my own musings. Aquinas was not a reader of science fiction.

 

[John_Hiner]

Here is a definition from a 1828 dictionary. The first definition seems close:

SUB’TIL, a. [L. subtilis. This word is often written subtle, but less properly.]

1. **Thin; not dense or gross; as subtil air; subtil vapor; a subtil medium. **
2. Nice; fine; delicate.
   I do distinguish plain
   Each subtil line of her immortal face.
3. Acute; piercing; as subtil pain.
4. Sly; artful; cunning; crafty; insinuating; as a subtil person; a subtil adversary.
5. Planned by art; deceitful; as a subtil scheme.
6. Deceitful; treacherous.
7. Refined; fine; acute; as a subtil argument.
   Here is a Latin dictionary definition for “subtilis”:
   perseus.tufts.edu/cgi-bin/ptext?layout.reflang=la;layout.reflookup=subtilis;doc=Perseus%3Atext%3A1999.04.0059%3Aentry%3D%2346165

 

[Ghosty]

Indeed, as others have pointed out, subtle is like “air” in that it flows into whatever it touches wherever it can. Dust is subtle, air is subtle, water is subtle. Spirit is subtle even beyond these material things, because it “is wherever it is acting”, for example how our soul permeates every part of our body.

Peace and God bless!

 

[thistle]

In the Modern Catholic Dictionary by John A. Hardon,S.J. the definition of subtility is:

Quality of the glorified human body which St Paul calls “spiritualised”. It is not, however, to be conceived as a transformation of the body into spirit or as a refinement into an ethereal substance. The prototype is the risen body of Christ, which emerged from the sealed tomb and penetrated sealed doors. The basis for subtility lies in the complete dominion of the body by the transfigured soul.

 

[John_Hiner]

In the Modern Catholic Dictionary by John A. Hardon,S.J. the definition of subtility is:

Quality of the glorified human body which St Paul calls “spiritualised”. It is not, however, to be conceived as a transformation of the body into spirit or as a refinement into an ethereal substance. The prototype is the risen body of Christ, which emerged from the sealed tomb and penetrated sealed doors. The basis for subtility lies in the complete dominion of the body by the transfigured soul.

The accounts of Jesus after the resurrection have always been connected in my mind with incidents like this:

When the people in the synagogue heard this,
they were all filled with fury.
They rose up, drove him out of the town,
and led him to the brow of the hill
on which their town had been built,
to hurl him down headlong.
But he passed through the midst of them and went away.

Luke 4:28-30 (NAB)

Anyone have any thoughts on this?

Pax.

John Hiner