Metaphysical and logical arguments for the existence of God

During the history of philosophy and theology, many arguments for and against the existence of God have been made. The God in question here is what is sometimes called the God of the philosophers, namely the God of the great religions of the Book (Judaism, Christianity, Islam), as he was conceptualized by the philosophers. His attributes are to be the creator of the world, omniscient, omnipotent, omnipresent and good.

Arguments for the existence of God

Metaphysical and logical arguments

Ontological argument

This argument has been proposed many times, it can be formulated in the general form of the following syllogism:

1. God is a perfect being.
2. A perfection which did not include existence would obviously not be complete.
3. So God is also endowed with existence.

A famous version is that of Anselm of Canterbury, in his Proslogion. His argument is that God is being such that nothing can be thought of as greater, and that in the mind as well as in reality. Thus, according to him, thinking of the greatest being, we cannot really think that God is not: the thought of God implies his existence. Gaunilon and then Thomas Aquinas will object to this argument.

Descartes proposed another version: “[…] I cannot conceive of God without existence, it follows that existence is inseparable from him, and therefore that he truly exists: not that my thought can make it happen. in this way, and that it imposes no necessity on things, but, on the contrary, because the necessity of the thing itself, namely the existence of God, determines my thought to conceive it in this way. Because it is not in my freedom to conceive of a God without existence (that is to say a supremely perfect being without a sovereign perfection), as I am free to imagine a horse without wings or with wings .”

The ontological argument has undergone many refutations, the general principle of which is that the existence of a thing can only be proved from its observation and not from its definition. The first philosopher to attempt to refute this argument is Gaunilon, who objects to Anselm immediately after the publication of the Proslogion. After him, Kant devoted a long part of Book II of the Critique of Pure Reason to refuting the ontological argument on which, according to him, two other great arguments for the existence of God, the cosmological proof and the physical-theological  proof (call to design), rest.

For Kant, existence is not an intrinsic property, one cannot legitimately say that existence belongs to the concept of God: it is to confuse the conceptual content and the existential predicate of a thing. Thus for Kant, the concept of God remains the same, whether he exists or not: this “concept of God” proves nothing, indicating only a possibility. To illustrate this, Kant takes the following example: “One hundred real thalers contain nothing more than one hundred possible thalers. Because, as the possible thalers express the concept and the real thalers, the object and its position in itself, in the event that the latter contains more than the former, my concept would not be the adequate concept. But I am richer with a hundred real thalers than with their simple concept (that is, with their possibility).”

Cosmological argument or first cause argument

The cosmological argument is a type of argument that relies on certain characteristics of the universe in order to demonstrate the existence of a first cause, generally understood as being God. It is today much discussed by analytical philosophers in the version known as Kalâm readapted by William Lane Craig in 1979. According to the philosopher Quentin Smith, “”a count of the articles in the philosophy journals shows that more articles have been published about Craig’s defense of the Kalam argument than have been published about any other philosopher’s contemporary formulation of an argument for God’s existence.”

Craig’s argument can be summed up in two premises leading to a conclusion:

1. Everything that begins to exist has a cause for its existence.
2. The universe began to exist.
3. If 1) and 2) are true, then 3) the universe has a cause of its existence.

To attempt to demonstrate the probability of the first two premises, Craig uses general metaphysical principles (premise 1), philosophical (notably the impossibility of a truly infinite number of past events) and scientific arguments, including the Big Bang theory. (premise 2).

History and variants

The first reference to this argument is found in Plato (Laws, VIII, 4-6), then it is developed by Aristotle in his Metaphysics (XII, 1-6). The cosmological argument is taken up in the Middle Ages by Muslim philosophers like Al-Kindi, then by Saint Thomas Aquinas and at the time of the Enlightenment by Leibniz and Samuel Clarke.

This argument can be divided into three main groups:

1. The impossibility of an infinite and ordered backtracking (Thomas Aquinas).
2. The principle of sufficient reason (Leibniz and Clarke)
3. The impossibility of a universe without beginning in time (Kalâm)

Kant proposed an indirect refutation based on the ontological argument. According to him, after having observed the contingency of the world, the cosmological argument must posit the existence of a necessary being; he is then obliged to resort to the ontological argument, which deduces from the concept of God that he exists. However, the ontological argument is invalid, therefore the cosmological argument is also, according to this reasoning of Kant.

(Translated from Wikipedia)