The view that we know God exists is called theism. The position that we know God does not exist is called atheism. The belief that we cannot know whether God does or does not exist is labeled agnosticism.
Two Kinds of Agnosticism
One form of agnosticism claims that we do not know if God exists; the other insists that we cannot know. The first we will call “soft” and the second “hard” agnosticism. We are not here concerned about “soft” agnosticism, since it does not eliminate in principle the possibility of knowing whether God exists. It says in effect, “I do not know whether God exists but it is not impossible to know. I simply do not have enough evidence to make a rational decision on the question.” We turn, then, to the “hard” form which claims that it is impossible to know whether God exists.
Impossibility of Knowing God Exists
Most modern forms of agnosticism have their roots in the thought of Immanuel Kant. While Kant himself believed in God, he felt, nonetheless, that no one could know God existed. There are, he felt, two basic reasons for this rational agnosticism.
Appearance/reality disjunction. Everything we know comes to us through our senses a posteriori, but it is formed and categorized a priori by the categories of the understanding (see p. 89). The mind without the senses is empty, and the senses without the mind are blind. That is, the content or “stuff” of knowledge is provided through sensation but the final form or structure of knowledge is given by the mind.
This being the case, there is no way for the mind to know reality (the noumena). We know things only after they are formed by the mind, not before. Only the thing-as-it-appears-to-me is known, not the thing-in-itself. In Kant’s terms, one can know only the phenomena, but not the noumena. And since God is a noumenal reality, then it follows that God cannot be known by pure reason.
Kant argued that all attempts to know God by pure reason fail because they illicitly assume an ontological argument. They may begin from experience of the phenomena (as in the cosmological argument), but sooner or later they go beyond experience by assuming (illegitimately) an ontological concept of a Necessary Being. But this is precisely what cannot be done, because there is “a great gulf fixed” between noumena and phenomena.
We cannot get beyond appearance to reality. Hence, any such argument, cosmological or otherwise, is doomed to failure.
Antinomies of reason. There is a second reason Kant gives for the impossibility of
rationally knowing or proving God. He points out that contradictions result whenever one assumes that the categories of the mind apply to reality. These paradoxes of pure reason prove that reason has wandered “out of bounds.” The proper role of reason is within the phenomena of experience. Reason cannot penetrate the noumenal thing-in-itself. One can know only that the world-in-itself is, but not what it is.
Kant gives a number of examples of these antinomies of reason. Each thesis is opposed by an antithesis, both of which must be posited but neither of which is compatible with the other when applied to the real world. For instance, thesis: there must be a first cause of the world, since everything must have a cause; but, antithesis: there cannot be a first cause, for if everything needs a cause then so does the first cause, and so on infinitely. Hence, we are left with the impossibility that opposites are true. Since this is impossible we must give up the hope that reason applies to noumenal reality. We are left, then, with complete
agnosticism. Reality cannot be known. And what applies to reality as a whole includes God in particular.
We must live as if there is a God. Giving up the knowledge of God is not the same as giving up God. In fact, Kant was a devout believer in God. He insisted that men could not—or at least should not—live without God. All men, Kant argued, seek happiness in harmony with duty. But such is not attainable without positing the existence of God. Hence, what we cannot prove by pure reason we must posit by practical reason. That is, we must live as if there is a God. However, we must never by theoretical reason try to prove the existence of God. We must remain agnostic because of the very nature of the knowing process.
Evaluation of Agnosticism
There are three basic criticisms of the “hard” form of agnosticism.
Not all reasoning leads to antinomies. It may very well be that antinomies prove that some reasoning is not valid about reality. Zeno’s paradoxes, for example, may prove that some reality (for example, the world of space and time) is not infinitely divisible. However, not all reasoning need end in antinomies. Indeed, some of the very examples Kant uses are not genuine antinomies. In these cases either the thesis or antithesis is not true, or else an underlying premise is false. For instance, Kant assumes that the principle of causality implies that everything must have a cause. But if one assumes that only contingent things need a cause, then contradiction does not follow.
Basic categories of the mind must apply to reality. Implicit in Kant’s argument from antinomies to agnosticism is the premise, “No contradictory premise can be true about reality.” This is precisely why Kant says that pure reason cannot apply to reality—because it ends in contradiction. But if the rational law of non-contradiction applies to reality, then there is at least one principle of the understanding that applies to reality. In fact, since the principles of identity and excluded middle (see p. 168) are inseparably related to the principle of noncontradiction, Kant allows that at least these principles of reason apply to reality. Further, Kant admits we know that reality is there (though we do not know what it is) and that it is the cause of the phenomena we do know. But if he claims that the noumena is causing the phenomena, then he has himself applied the principle of causality to the noumenal realm.
Inconsistent nature of total agnosticism. Another way to state this objection to Kant’s agnosticism is to point out that it is inconsistent to affirm that one knows that he cannot know anything about reality. How can one know this without some knowledge of reality? If the agnostic insists that he is not making any positive statement about reality but only a negation (that he cannot know it), then this too is impossible. Every negation is actually a definite statement which implies some positive knowledge. How can one know for certain what reality is not unless he knows something of what it is by contrast?
Some agnostics may claim that they cannot know infinite reality (that is. God) but only finite reality. But even here there are several problems. First, the very denial of knowledge of an infinite implies some knowledge of the infinite. One must know what cannot be denied of God if he knows what can be denied of God. Further, when one says, “I cannot know the Infinite,” another may justly ask, “You cannot know what?” If the agnostic does not have some knowledge of the infinite, then the very denial is meaningless, since he cannot know even the meaning of the term infinite in his denial.
If the denial means only that one cannot know the infinite infinitely, then most theists would readily agree. Man is finite and hence cannot know in an infinite way. But this limited agnosticism, which humbly admits it does not have an infinite understanding of the infinite, is a long way from denying all knowledge of the infinite.