First Cause

First Cause is a philosophical term introduced by Aristotle. Aristotle noted that things in nature are caused and that these causes in nature exist in a chain, stretching backward. The cause of the cat you see today, for example, was its parent cats, and the cause of those parents were the grandparent cats, and so on. The same for the oak tree you see; it was caused by an acorn from a previous oak tree, which in turn was caused by an acorn tree from a previous oak tree, and so on, stretching back to whenever.

The question about such causal chains, raised by Aristotle and others, is whether they must have a terminus or starting point. Aristotle, and others following him, claim that the answer is yes, that there must be a First Cause because such causal chains cannot be infinite in length.

Theists, such as Thomas Aquinas, identify this First Cause with God, and use this argument, usually known as the argument from causation, as an argument for the existence of God. This argument was the second of Aquinas's Five Ways of proving (he thought) the existence of God.

The first cause argument rests on several assumptions or premises. The first is that beings are not the cause of themselves. The second is that there must be an exception to that first premise or assumption; there must be a being that (who) is the cause of itself (himself). Thus Aristotle and others who accept and use this argument say that the first cause is different from all other beings in that the first cause is self-caused. How this self-cause exists or how it came about (if it did—the other possibility is that it is infinite in duration into the past) are unexplained.

Another assumption of the first cause argument is that there is only one such first cause. Stricly speaking, this assumption is an extraneous one because first cause arguments, by themselves, would permit any number of such first causes.

First cause arguments say nothing about the character or characteristics of the first cause—whether that being is beneficient and good or malevolent and evil or some combination of those, whether that being is personal or impersonal, whether that being has desires and intentions, or other such questions To solve those questions, additional evidence or argument is needed, none of which comes from or is supplied by the first cause argument itself.