InSearchOfGod:
What is substance? What is it made of? God is not made of atoms, there must be more to it . . .
Exactly.
‘Accidents’ are things that describe something, it’s shape, it’s color, anything can be detected via the senses (which does include atoms)
‘Substance’ is what something truely IS.
If you changed your hair style, or even painted your entire body red, you have changed your accidents, but you are still you. Your substance did not change.
If a Star Trek style transporter changed every single atom in your body, you would still be you, you would not be a completely different person.
That is becasue there is more to ‘you’ than a collection of atoms, or a hair style or a particular color of skin. Something deeper than the physical, something the physical only describes.
THAT is Substance.
In the Eucharist, God is present, but the description of Him being Present co-incides with that of bread and wine.
Everthing we can physically describe about bread describes his Presence.
But a description is not a Reality!
Just as describing something does not make it Real, Reality is not made or defined by it’s description. The Reality is that God is in front of us.
I hope this makes some sense, it’s really just a very poor paraphrase of St. Thomas Aquinas. He saying things so much better than I could ever hope for.