DAY 73
CHALLENGE
“What proof do you have that God exists?”
DEFENSE
One popular proof proceeds from the existence of change in the universe.
The argument can be framed this way:
1. Some things in the world change.
2. Everything that changes is caused to do so.
3. Nothing is its own cause.
4. Therefore, things that change are caused to do so by something else. 5. There cannot be an infinite regress of such causes.
6. Therefore, there is an ultimate, unchanging cause of change.
7. God is the ultimate, changeless cause of change
8. Therefore, God exists.
The premises of this argument are lines 1, 2, 3, 5, and 7. The conclusions (lines 4, 6, and 8) follow from them.
Line 1 is proved by observation: we see constant change in the world around us.
Line 2 is a truth of metaphysics. It is also verified by observation. Whenever we see something change, there is a cause for this change. Line 3 is a truth of metaphysics. The idea of one thing ultimately being its own cause is incoherent.
Line 5 is a truth of metaphysics. Consider an analogy: if a painting is being made then paint is being applied to a canvas. The paint is moved by the bristles of a brush. The bristles are moved by the wood of the first inch of the handle to which they are attached. The wood of the first inch of the handle is moved by the wood of the second inch, which is moved by the wood of the third inch. However, the handle cannot go on forever. Ultimately, the handle is moved by an artist. To suggest otherwise would be to suggest “that a brush can paint by itself, provided it has a very long handle” (Antonin Sertillanges, quoted in Reginald Garrigou-Lagrange, God: His Existence and His Nature, 265). In the same way, there cannot be an infinite regress of simultaneous causes.
Line 8 is true by definition.
TIP
This is a version of St. Thomas Aquinas’s “first way” of demonstrating God’s existence (ST I:2:3). It’s sometimes called the argument from “motion,” since Aquinas refers to what we call change as motion.