Aquinas says light is not material
Good afternoon,
I wanted to cite the arguments of Aquinas from the Summa Theologica in which he tries to say that light is not material. In his medieval system, aesthetics precedes science so that what seems most pleasing to their intellectual bent is assumed to be true.
Now he first says "Two bodies cannot occupy the same place simultaneously. But this is the case with light and air. Therefore light is not a body." This is not a very good argument because light and air do not reside in the same points of space as the other but can nonetheless be in the same general area according to our perception. He then goes on to say that light from the Sun to the Earth must be instantaneous, which actually just goes to show how he doesn't understand physics and mathematics:
"Nor can it be argued that the time required is too short to be perceived; for though this may be the case in short distances, it cannot be so in distances so great as that which separates the East from the West. Yet as soon as the sun is at the horizon, the whole hemisphere is illuminated from end to end. It must also be borne in mind on the part of movement that whereas all bodies have their natural determinate movement, that of light is indifferent as regards direction, working equally in a circle as in a straight line. Hence it appears that the diffusion of light is not the local movement of a body."
None of these are good arguments and he is using philosophy to analyze physics. This was the tendency of the times which regarded Aristotle's aesthetics as primary over truth.
Aquinas goes on to say that although it can be argued that "every sensible quality has its opposite, as cold is opposed to heat, blackness to whiteness" it "is accidental to light not to have a contrary, forasmuch as it is the natural quality of the first corporeal cause of change, which is itself removed from contrariety."
This is based on the idea that the stars are quasi-supernatural. The medievals were as interested in light as the moderns. In the Middle Ages the only things in the universe closer in substance to God then the heavenly bodies were human souls.
I think the main mistake of the scholars of this period was that they had a particular liking for very specific abstract forms of philosophical think and this prevented them from trying experiments and testing what the universe really was. In a way, this was Christian philosophy resisting the pull of materialism and the the idea that we get our knowledge of the world from science. If it wasn't for thinkers who rejected scholasticism, such as Descartes and Galileo, this would have prevented the rise of the modern technological world, for good or for bad
I wanted to cite the arguments of Aquinas from the Summa Theologica in which he tries to say that light is not material. In his medieval system, aesthetics precedes science so that what seems most pleasing to their intellectual bent is assumed to be true.
Now he first says "Two bodies cannot occupy the same place simultaneously. But this is the case with light and air. Therefore light is not a body." This is not a very good argument because light and air do not reside in the same points of space as the other but can nonetheless be in the same general area according to our perception. He then goes on to say that light from the Sun to the Earth must be instantaneous, which actually just goes to show how he doesn't understand physics and mathematics:
"Nor can it be argued that the time required is too short to be perceived; for though this may be the case in short distances, it cannot be so in distances so great as that which separates the East from the West. Yet as soon as the sun is at the horizon, the whole hemisphere is illuminated from end to end. It must also be borne in mind on the part of movement that whereas all bodies have their natural determinate movement, that of light is indifferent as regards direction, working equally in a circle as in a straight line. Hence it appears that the diffusion of light is not the local movement of a body."
None of these are good arguments and he is using philosophy to analyze physics. This was the tendency of the times which regarded Aristotle's aesthetics as primary over truth.
Aquinas goes on to say that although it can be argued that "every sensible quality has its opposite, as cold is opposed to heat, blackness to whiteness" it "is accidental to light not to have a contrary, forasmuch as it is the natural quality of the first corporeal cause of change, which is itself removed from contrariety."
This is based on the idea that the stars are quasi-supernatural. The medievals were as interested in light as the moderns. In the Middle Ages the only things in the universe closer in substance to God then the heavenly bodies were human souls.
I think the main mistake of the scholars of this period was that they had a particular liking for very specific abstract forms of philosophical think and this prevented them from trying experiments and testing what the universe really was. In a way, this was Christian philosophy resisting the pull of materialism and the the idea that we get our knowledge of the world from science. If it wasn't for thinkers who rejected scholasticism, such as Descartes and Galileo, this would have prevented the rise of the modern technological world, for good or for bad
Comments (35)
They are useful things. They serve to group the sections of your post, and make it much more readable. Consider:
Quoting Gregory
Isn't that better?
Christianity invented the Dark Ages, and had to be pulled out of it kicking and screaming.
Thanks
What do you mean? Light is electric and magnetic, presenting itself as particles while being a wave through the reality of spacetime
We have no evidence of any of that. Only of patterns of colors and sounds:
According to bundle theory, an object consists of its properties and nothing more; thus, there cannot be an object without properties and one cannot conceive of such an object. For example, when we think of an apple, we think of its properties: redness, roundness, being a type of fruit, etc. There is nothing above and beyond these properties; the apple is nothing more than the collection of its properties. In particular, there is no substance in which the properties are inherent.
And the properties of light are electricity and magnetism
That is all just words that stands for maps in the mind that represent patterns of sense data which is patterns of colors.
So light is a color? How is it that you feel comfortable rejecting proven data without even giving counter arguments?
No.
Light does not exist. We only have evidence of colors, patterns of colors, and changing colors. When a color changes you claim it was because some mysterious "light" shined on it.
And there's the mental illness. You know what a car is right? If it hits you you really think it will only be colors hitting you? Scientists have analyzed light the same as they have studied combustion.
You should know about a book called God's Philosophers, James Hannam. It debunks many of the popular myths about the medieval period.
___
Quoting Gregory
That is based on an argument in the Phaedo 103c onwards.
That said, agree that Aquinas speculations on the nature of light don't deserve to be considered scientific, although, on the other hand, light does seem to occupy a special place in the grand scheme.
Certain patterns of color are associated to certain other patterns and also certain feelings like pain.
This is no way proves matter or light exists outside of our ideas.
We can see light. Matter is not just colors and we know it exists. Apparently you're a solipsist
I have not presented myths. Aquinas says that the planet's other than earth were right below the human soul in their god-like nature, being incorruptible and the noblest of matter (fire being a lower form of them). This is just pagan mysticism
We see colors changing color, and explain it with the idea that light shined on it and changed the color (hue)
You need to study more
You need to study less and look more.
"medieval people did not think the earth is flat"
Most people know this
"nor did Columbus 'prove' that it is a sphere"
Nobody says he landed in China lol
"the Inquisition burnt nobody for their science"
If it contradicted the Bible or "true" philosophy, yes they did.
"nor was Copernicus afraid of persecution"
He was faithful to Christian philosophy
"no Pope tried to ban human dissection or the number zero"
Many bishops did.
You don't write like you know very much. Start with this:
https://www.youtube.com/watch?v=M90XEREe66s
Try to learn
Quoting Gregory
Did I say that you did?
I never said those theories were invalid. I only said there is no actual evidence of matter or light. But only colors, sounds, feelings, etc...
To be fair, modern day speculations on the nature of light do not deserve to be called "scientific" either. Even the conventional description, "wave/particle duality" cannot be said to be scientific because of the incompatibility between "wave" and "particle" demonstrated by the incoherency of the observations, the "collapse".
Aquinas claims cold is a quality and darkness not and does so dogmatically, without evidence and without research. Science studies how light behaves and describes how these experiments show something physical about light itself. If you want to say that on top of this light has a quality nature well that's just philosophy and not what this thread is about. All the modern gadgets were not invented by random but took research and insight into the nature of reality
You are criticizing 13th century science and philosophy on the basis of 21st century physics. I don't see how that accomplishes anything substantive.
I quoted Aquinas's arguments on why he thought light was immaterial. Just as people quote and criticise Aristotle's physics.. There are people who still believe this stuff and reject science
Criticizing either from 1,000 or 2,000 years in the future is pointless. Both are important for historical reasons. Both come from periods before there was a distinction between science and philosophy.
It's just a general thread about medieval thought. If you don't like it go away
Your opening post was intellectually misleading. I pointed it out. I will go away now, unless you keep it going.
You will not go away. You shall engage with me and Gregory until we discover a new paradigm in physics and understanding of reality.
Yes, master.
The man was ahead of his time, and if I'm not mistaken shared ideas that modern science has springboarded off of. Two bodies perhaps being the primal elements being earth, wind, water, and fire. Light has a uniqueness, clearly. Obviously earth being opaque is an exception but as far as the other elements this element definitely has a curious place.
Aquinas got the four elements from the Greeks and the superiority of light over matter from Aristotle and Augustine