Argument from divine sense

The argument from divine sense, or sensus divinitatis is an attempt to justify reformed epistemology, which holds that belief in God can be considered properly basic, requiring no external justification. This particular argument has seen resistance from both believers and non-believers, though for fundamentally different reasons. Believers point out that the argument not only eliminates any need for traditional apologetics that attempt to offer rational defenses of faith and belief in God, it also eliminates traditional views of faith, encouraging a position akin to "God is real for me, and that's all that matters." Additionally, theists and non-theists point out that even if the argument were sound, it cannot justify any particular God or concept of God beyond what the individual claims to experience.

For an example of this argument in action, one can listen to the Atheist Experience Episode #455 at about 21.5 minutes into the show.

Foundationalism premise
The underlying premise for the argument rests in the concepts of foundationalism, which holds that beliefs can be divided into two categories:
 * 1) foundational beliefs (also called basic or properly basic), which are accepted axiomatically and require no external justification;
 * 2) all other beliefs, which are derived from foundational beliefs.

Foundationalism is not universally accepted, and competing epistemological philosophies exist which include objections to the premise of properly basic beliefs. (See Foundationalism or our own article, Foundationalism for more information.)

Basic argument
One formulation of the basic argument from divine sense (tuned to Christianity, as Christian philosophers like Alvin Plantinga have been the major proponents of this claim):
 * Premise 1 (P1) - If Christianity is true, it is very probable that humans are endowed with a cognitive faculty in addition to memory, perception, etc. which we can call the sensus divinitatis
 * Premise 2 (P2) - If humans have a sensus divinitatis, then Christian belief can be foundational
 * Conclusion (C1) - If Christianity is true, (very probably) Christian belief can be justified, without independent evidence.

Existence of SD

 * &rarr; See main article on sensus divinitatis

In P1, we see "If Christianity is true, it is very probable that humans are endowed with a...sensus divinitatis." Those who accept this reformed epistemology assert that Christian teachings necessarily support the existence of SD and that this assertion can only be challenged on exegetical grounds. They hold that a number of passages in the Bible imply or affirm the notion that God has given everyone a mechanism for knowing and understanding his nature.

This assertion isn't accepted, to the same degree, by all Christians and additional passages from the Bible along with testimonials from believers clearly claim that God can, and does, interact with the physical world in empirically observable ways, not the least of which is the Christian doctrine that God came to earth in a physical form to deliver the most important message in Christendom. This sort of physical interaction would not be necessary if a properly basic SD existed.

Reliability of SD
In P2 we see, "If humans have a sensus divinitatis, then Christian belief can be foundational."

This raises questions about the reliability of claims attributed to a sensus divinitatis. If we operate under the assumption that SD exists:
 * How do we explain the lack of such claims from the non-religious?
 * How do we explain contradictions between scientific knowledge and claims of divinely revealed knowledge?
 * How do we explain the many inconsistent and/or contradictory claims about god/God/gods made by members of various religions - including members who profess to be of the same religion?

There are more than 1000 denominations within Christianity and there have been many other religions and sects which claim to worship the same God, rely on many of the same scriptures and have claimed rough equivalents of SD. To even the most casual observer, this situation should call the reliability of claims regarding SD into question.

Why SD is unreliable
One common claim among apologists is that humans were created with a perfect sensus divinitatis, but after man sinned by eating from the tree of knowledge, part of his punishment was a separation from God which rendered this divine sense unreliable. They claim that this broken SD will be repaired, for true believers, by God. Some of those who would use this argument would re-write P2 to read:
 * P2 - If humans have a properly working SD, then Christian belief can be foundational

Modifying premise 2 demonstrates the fundamental flaws inherent in making claims of divine revelation:
 * How do you distinguish SD from psychosis, delusion or wishful thinking?
 * How do you know whether or not your SD is working properly?
 * How do you know that your SD isn't being intentionally manipulated by Satan?
 * Wouldn't a truly evil and near-god-like being prefer to have you believe you're understanding God when you're really understanding him?

The unreliable and often contradictory nature of claims attributed to SD clearly ensure that it shouldn't be considered properly basic. This is only exacerbated by ad hoc explanations to explain the unreliable nature of these claims which seem to be desperate attempts to avoid the obvious conclusion - there is no sensus divinitatis.

Application to other religions
Yet another objection to this argument is that it doesn't create an argument that necessarily supports only Christianity. Consider the argument again, with another religion or belief replacing Christianity along with it's claim of something akin to sensus divinitatis. The conclusion will work for any claim which includes a method of self-confirmation.

The reason for this is obvious if we continue to simplify the argument...

Simplified argument
Consider this argument: If X(god answers prayer), Y(a double-blind study) will verify this. Yet double-blind studies have demonstrated that prayer appears to have no effect. The apologists' response is to claim that studies like this are unable to properly evaluate the effectiveness of prayer - essentially challenging P2 - because the test didn't use true believers, or because God won't be tested, or some other excuse.
 * P1 - If X is true, there should be some method of verifying this.
 * P2 - Y is a method of testing which is suitable for verifying X.
 * C1 - If X is true, Y will verify this.

As other refined Y-methods are tried, the results continue to fail to verify the efficacy of prayer. Instead of relying on the external justification (or dealing with the external invalidation) of Y, they opt for self-justification:
 * P1 - If X is true, X includes a method of self-verification, X'.
 * P2 - X' will be defined as 'properly basic'
 * C1 - If X is true, X' will be sufficient justification

Essentially, I know God answers prayers because he's answered mine. Or, continuing the reformation of the argument, This belief is true because I believe it.

This is extremely clear when we consider that we could make up any religion and declare that anyone who feels that the religion is true is, in reality, sensing God as he provides them with confirmation. If we expand this to state that those who continue to faithfully observe a specific set of rules and traditions will become more "in tune" with God and those who disobey will become less clear and in danger of damnation - we quickly promote a self-reinforcing delusion. In a group society, when a few trusted individuals buy into these claims, others will follow.

The core argument can be used to justify any religion which can be interpreted as having an internal mechanism of self-justification.

Conditional argument
The existence of several conditionals in the argument render it ineffective - "if Christianity is true", "very probable", "if humans have a sensus divinitatis". Even if it were valid and sound, the most it could ever prove is the possibility that the state of affairs it presents were true - and that possibility wouldn't be exclusive to any particular religion. Removing the conditionals removes this argument from the realm of the hypothetical and places the believer back in the position of having to defend the truth of the claims they make - and that's the real purpose of this argument: it is an attempt to avoid the burden of proof.