Contingent things cannot have an eternal past. By definition, contingent things are things that depend on something else to exist. First consider a tree. Let us take a closer look at the following three things: what a tree depends on, the forward moving life cycle of a tree, and the timeline of trees moving back into history.
- A tree is a contingent thing. It depends on many other things to exist. Under normal conditions, it needs sunlight, water, carbon dioxide, and nutrients from the soil. A tree does not cause itself to begin existing, nor does a tree cause itself to exist on its own.
- An oak tree is a finite living thing. It begins as an acorn, and a good acorn can sprout into a seedling under the right conditions. If it begins to grow in a good location, the oak tree can grow for many years. A tree is known to have growth rings that tell us the age. The dating and study of annual rings in trees is called dendrochronology. Oak trees such as a Northern Red Oak typically live for 200 years, although the California Black Oak can live to 500 years in certain locations. After a certain amount of time, the tree dies.
- Then the question becomes did a first tree begin at some point in the past or has it always been reproducing? Either the cycle of trees has an infinite regression or the cycle of trees is traced back to a first tree. According to the law of non-contradiction, the reproducing cannot both have a beginning and have an infinite regress. Let us consider both possibilities one at a time. Imagine an infinite amount of oak trees and an infinite amount of maple trees. How can each type of tree have an infinite amount, yet combined there are still an infinite amount of trees altogether? The paradox is that an infinite amount plus an infinite amount is still only an infinite amount. This is why scholars say an infinite regress of finite contingent things is impossible. There must be a finite amount of oak tree reproduction that traces back to a first oak tree. Furthermore, there must be a first cause that somehow caused the first oak tree to exist. Just as a hand causes the first domino to tip over onto the next domino and so on, so too does a first cause begin a series of tree reproduction. We call that first cause our Creator. Thus, creation implies Creator.