What is a standard of proof? How do we know what we know?


If someone asks a question, a standard of proof is the level of evidence needed to provide them with an answer.

For example, Bob asks Tom: “Is there a dog on the sidewalk?” and Tom says: “Yes. The neighbors are walking their dog, Spot.”

If Bob believes Tom, then his standard of proof was Tom’s word. All he needs from Tom is his promise that he is telling the truth. In fact, all Bob really needs is for Tom to tell him something for him to believe it.

However, if Bob asks Tom the same question, but demands photographic evidence of his claims, then his standard of proof has risen. Tom has to exert more effort to prove the same thing he is claiming.

Bob’s standard of proof increases even more if he demands video evidence or a spreadsheet of how often the neighbors walk their dog during the week. He may even demand that Tom gives him research from a third party if he doesn’t trust him.

Epistemology is the branch of philosophy that wants to answer the question: “How do we know what we know?” Identical questions are: “What is knowledge?” “When do we know something?” and “How sure is sure enough”?

Anyone who has played the Why Game was engaging in epistemology. The Why Game is simply asking someone a question and then asking them “why?” over and over again. The person always has another question to answer, and so the game is a way of being a nuisance. Philosophers play the Why Game in epistemology, and the game ends in three ways:

1. They arrive at a claim that can’t be proven, but it is true. (Foundationalism) 

2. They prove the most recent claim using the first. (Coherentism/Circular Reasoning)

3. They go on forever. (Infinitism) 

The third option, infinitism, fails to explain how people know anything, because it is just the game continuing. Nothing is explained.

The second option, coherentism, fails to explain how people know anything, because it is just circular reasoning. Circular reasoning is just restating a belief as a reason for it. This is an example of circular reasoning:

1. The Bible affirms that it is inerrant. 

2. Whatever the Bible says is true. 

3. Therefore, the Bible is inerrant. 

The first option, foundationalism, explains how people know anything, but it requires a leap of faith to believe the unprovable claim.

There are many unprovable claims people believe. For example, the belief that I am alive is true, but unprovable. I simply experience it as true. So why should anyone trust these unprovable claims? Isn’t it the job of the philosopher to make logical arguments so that claims are proven beyond a shadow of a doubt?

The problem with this reasoning is that if the standard of proof is a logical argument, then there is no way to remove all doubt. For example, this argument is the basic structure for all logical arguments about the world outside one’s mind:

1. All swans seen thus far are white.

2. We should trust what we have seen in the past to predict what we will see in the future.

3. Therefore, the next swan will be white.

But this argument is doubtful, because the future sometimes surprises us with new evidence. Some swans are actually black. Even strict standards of proof can sometimes fail to account for new things, for every single argument about the world follows the above pattern. There is no way to remove all doubt if the standard of proof is a logical argument using real-world evidence, since evidence can be limited, fallible or forged.

So how do we know things? Alvin Plantinga and William Lane Craig are Reformed epistemologists who offer slightly different answers. Alvin Plantinga says that a belief has warrant if the following conditions are met:

Wikipedia: Plantinga’s Reformed Epistemology

According to Plantinga, a belief, B, is warranted if:

(1) the cognitive faculties involved in the production of B are functioning properly…; (2) your cognitive environment is sufficiently similar to the one for which your cognitive faculties are designed; (3) … the design plan governing the production of the belief in question involves, as purpose or function, the production of true beliefs…; and (4) the design plan is a good one: that is, there is a high statistical or objective probability that a belief produced in accordance with the relevant segment of the design plan in that sort of environment is true.[21]

But this doesn’t address whether we are ever warranted in believing that his conditions are satisfied when we apply his criteria. Furthermore, why should we even believe in his criteria? One could always ask: “Why should we use your criteria, Plantinga?” So how does Plantinga respond to this objection? In his book, Warranted Christian Belief, Plantinga offers the following answer:

Warranted Christian Belief by Alvin Plantinga.pdf

I propose the extended A/C model; according to this model, Christian belief is warranted because it meets the conditions of warrant spelled out in Warrant and Proper Function. That is, Christian belief is produced by a cognitive process (the “internal instigation of the Holy Spirit” [Aquinas] or the “internal testimony of the Holy Spirit” [Calvin]) functioning properly in an appropriate epistemic environment according to a design plan successfully aimed at truth. Chapter 8, “The Extended A/C Model: Revealed to Our Minds,” sets out the cognitive side of this process. The process involves the affections as well as reason, however (i.e., it involves will as well as intellect), and chapter 9, “The Testimonial Model: Sealed upon Our Hearts,” explains some of the connections between reason and the affections.

In other words, the Holy Spirit works within our minds to help us understand the truth. This can be construed as spiritual common sense. One is justified in believing a claim, because God actively works in his mind to help him know the Truth. This process is alluded to in the book of Romans:

Romans 1:18-20

18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth. 19 For what can be known about God is plain to them, because God has shown it to them. 20 For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world,[g] in the things that have been made. So they are without excuse.

Romans 2

14 For when Gentiles, who do not have the law, by nature do what the law requires, they are a law to themselves, even though they do not have the law. 15 They show that the work of the law is written on their hearts, while their conscience also bears witness, and their conflicting thoughts accuse or even excuse them 16 on that day when, according to my gospel, God judges the secrets of men by Christ Jesus.

Romans 8:26-28

26 Likewise the Spirit helps us in our weakness. For we do not know what to pray for as we ought, but the Spirit himself intercedes for us with groanings too deep for words. 27 And he who searches hearts knows what is the mind of the Spirit, because[g] the Spirit intercedes for the saints according to the will of God. 28 And we know that for those who love God all things work together for good,[h] for those who are called according to his purpose.

Knowing what is true is very similar to knowing what is good. In a sense, human beings are built with a moral compass and an epistemological compass. Disobeying one’s epistemological compass is as bad as disobeying the moral compass, for it amounts to denying the Holy Spirit’s psychic intervention in one’s life.

This perspective also explains how people can err, for it is undeniable that some people have broken moral compasses: Christianity is the only rational belief system for answering moral questions. Likewise, some people have broken epistemological compasses.

William Lane Craig differs from Plantinga in his approach to spiritual knowledge. Here, he addresses the differences between his and Plantinga’s views:


Kevin Harris: This writer says that there are some differences between your warrant basic belief model and Plantinga’s. What difference is he pointing out here?

Dr. Craig: Well, I was glad to see that he was familiar with Plantinga’s reformed epistemology and correctly interprets my view as a species of that. Where we would differ is that Plantinga thinks of the Holy Spirit as akin to a cognitive faculty, whereas I think that the Holy Spirit’s witness to us is more akin to testimony; beliefs based on testimony. For example, if I meet you and you say to me “my name is Kevin,” I believe that in a properly basic way based upon your testimony. And I think that the witness of the Holy Spirit is more like that than like an inter-cognitive faculty that I have. So, this would be a minor difference between us, but nevertheless, a difference.

The basic idea remains the same between Plantinga and Craig. God supernaturally intervenes via the epistemological compass. Just like the moral compass described in Romans, the epistemological compass is a spiritual faculty.

Problems of belief and skepticism always exist in philosophy. There is no way to solve these difficulties without appealing to a supernatural force for standards of proof can always be raised. However, this doesn’t mean that true knowledge is impossible, for our compasses show us the way. People who deny the Truth in spite of the evidence cannot be convinced, because the root issue is their broken compass.

Christians solve these fundamental epistemological problems through their belief in a supernatural being. God is the Truth in epistemology just as He is the Good in morality. God is the foundation for the Christian worldview, and Jesus is the cornerstone who intervenes through the Spirit.

Relevant Materials

Warranted Christian Belief by Alvin Plantinga

Wikipedia: Plantinga’s Reformed Epistemology





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