The Cosmological Argument

A logical proof of G-d's existence based on Duties of the Heart by Rabbi Bachya ibn Paquda

Summary:

1. Every finite being has a cause.
2. Nothing finite can cause itself.
3. A causal chain cannot be of infinite length.
4. Therefore, there must be a first cause which is not itself an effect.This is called G-d.

Explanation:

1. Every finite being has a cause.
If it is finite, that means that it began at some point in the past. That means that something caused it to begin.

2. Nothing finite can cause itself.
It cannot cause itself because this would be accomplished either before it existed or after it existed, both of which are impossible. It cannot cause itself before it existed, because it did not exist yet to effect the cause. It cannot cause itself after it existed. It was already in existence at the time and so nothing was accomplished thereby.

3. A causal chain cannot be of infinite length.
It is not possible for something infinite to have parts, because a part is defined as a fraction of the whole.
If a part is removed from an infinite object, then it will be less than it was before. This remainder will be either (a) infinite or (b) finite.
(a)If the remainder is infinite, than this infinity is less than the previous one. Infinities cannot be one greater than the other, for infinity is always greater.
(b)If the remainder is finite, and the part which is removed is returned, then the sum will also be finite. This is a contradiction and therefore false, for we said that the whole is infinite.
Therefore, anything that has parts must be finite.
In a causal chain, each cause is a part of the chain. Therefore a causal chain must be finite. It must have a limited number of antecedents, which end at a cause that has no cause before it.

4. Therefore, there must be a first cause which is not itself an effect. This is called G-d.
There must be a beginning to the causal chain of every finite thing, since every finite thing has a causal chain which does not go on forever. This beginning must be infinite, or else it, too, would require a cause.

That means that it is infinite in time, existing eternally without a time at which it began, as well as space, not having any component parts or a delimited region that it occupies. Since it caused all finite things, being all the objects and properties that we know, it therefore has the ability to effect and exhibit all objects and properties, and since it is infinite, it can do so in infinite measure. This includes the property of intelligence. The first cause exists to a greater degree than other things because it's existence is inherent and not contingent on the existence of anything else, whereas the existence of all other things is contingent on it and so merely provisional.