Change: Change must occur. An experiment consists of something changing from state X to state Y, and afterwards reasoning from premises to conclusion. So the mere act of observing, testing, and concluding about one's environment presupposes that change occurs.
It can't be emphasized enough that this defense of the existence of God depends not upon the specific scientific facts of our world, which is how Intelligent Design and creationists argue their case, but rather upon the facts that would have to be true of any world that we can have scientific knowledge of, no matter what that specific knowledge turns out to be. We are operating on a very fundamental and abstract level in this series of posts.
So change occurs. That is, something goes from one way, to another way. When it was the first way, it was possibly the second way. If it wasn't possibly the second way, then the change never would have occurred.
So change entails that changeable things are a mixture of the way they actually are now, and the way the possibly could be if they change. Most things of our experience are a composite of actual and possible.
Since a possible future state is merely possible, it is not real or actual yet, and therefore cannot make itself actual. So something already actual needs to make the possible actual. To take a concrete example, liquid water is possibly ice, but actual cold air must change the water into ice. It can't change itself into ice.
This distinction also applies at more general levels as well, such as existence. For example, it is possible that tyrannosaurs exist, but they are not real, or actual. It is possible that elephants exist, and it also turns out that they actually do. Here again, something cannot make itself real or actual, for that would mean it would have to exist before it exists, which is a logical contradiction. So something else real or actual must make these possibilities actual. We are thinking here in terms of what sustains something in existence from moment to moment, not what caused it to begin to exist. The elephant's parents may have caused its life to begin to exist, but they do not sustain the elephant in existence throughout its life. What does that would be atomic strong and weak forces, the state of electrons, gravity, atomsphere, and so on.
So the take-home thought is:
- Anything that is changeable or possibly existent/non-existent is a mixture of actual and possible
- Anything that is a mixture of actual and possible cannot make itself actual, and thus must be made actual by something that is already actual