Is Faith Irrational?

Updated: Jan 4, 2019

For the Head... [2nd in a 2 part series]. [link to part 1]

In the previous post, we have seen that faith is ‘to hold something for true which we ourselves cannot directly know or prove.[1] We also saw that we hold something for true because we trust the person who communicated that truth to us. Nevertheless, even if faith is reasonable, would it not be better, more certain, to know that to believe? Additionally, can the arguments in favor of a natural faith legitimately support the reasonableness of a religious faith?

a. Faith vs. Knowledge

A person might hold that, ‘Direct empirical knowledge is better than faith when it comes to arriving at truth. Faith alone seems tenuous at best, a second rate solution.

How do we know anything directly? There are two routes: experience and deduction.

I know something through experience to be true because I have seen it to be so. For example, I know that when I let go of an apple, it will fall down and not up. I see the law of gravity in action. This principle is the foundation of the empirical sciences: our repeated experiences, or experiments, confirm our theories about the material reality around us.

The other means of knowledge is deduction. Logical deduction ‘is the process of reasoning from one or more statements (premises) to reach a logically certain conclusion… If all premises are true, the terms are clear, and the rules of deductive logic are followed, then the conclusion reached is necessarily true… (For) example: 1. All men are mortal. 2. Socrates is a man. 3. Therefore Socrates is mortal.’[2] That is, our intellect, while starting with the senses, is able to grasp truths beyond the merely empirical.

Faith is the third way by which we can arrive at the truth, through the mediation of a messenger. The reality we access by faith is no less true for having arrived at it by faith. So if the plane is really in good flying condition, that truth is independent of whether I personally check it or if someone else checks it, or for that matter, if no one checks it.

Now, one might argue that my faith could be mistaken, which is possible. However, it is also possible that his or her experience or deduction could be mistaken. Have you ever taken one person for another at a first glance? Have you ever gotten a logical process, like a math problem, wrong? Who hasn’t? Both direct knowledge and the mediated knowledge of faith have failed us in the past, but both have also led us to truth.

I would even argue that faith could be more certain than my own experience, because if the person telling me about something knows more about the subject than I do, it is more reliable. My mechanic can give me more information about what is wrong with my car in five minutes than I can ascertain by looking at it an entire day. The very system of education relies upon faith: you trust that your professors or teachers know more about a given subject than you do. Rarely do you crosscheck the information given in a classroom, and even less so in a textbook. You believe them because you trust them. Only peer-reviewed articles would come under some scrutiny, and then, only by the peers, and not by everyone who reads them.

b. Natural Faith vs. Faith in God

However, even if a natural faith is legitimate, does that legitimize faith in God? Put another way, is faith in God any different that a ‘natural’ faith? Some would argue that, ‘Faith in the airplane’s fly-worthiness and faith in God are two completely different things. They are on two completely different levels!’ I would agree, because all the examples I have previously given are ultimately empirically provable. We cannot do this with God, who by definition, is immaterial. Let us consider two points.

First, whereas the nature of the object is different, the immaterial God vs. the material airplane, the structure of faith remains the same: you hold something to be true because you trust the person who told you that it was so. As such, we have seen that per se the act of faith is not irrational.

Secondly, while our Christian faith remains faith, it does not mean that it is a complete stab in the dark, a jump into irrationality. There are many hints or ‘signs’ of God’s reality in this world, which inductively point to the reality of a higher being, such as: an ordered universe, man’s spiritual reality and his wrestling with morality, among other things.[3] As Chesterton’s writes in Orthodoxy: If I am asked, as a purely intellectual question, why I believe in Christianity, I can only answer, "For the same reason that an intelligent agnostic disbelieves in Christianity." I believe in it quite rationally upon the evidence. … But the evidence in my case, as in that of the intelligent agnostic, is not really in this or that alleged demonstration; it is in an enormous accumulation of small but unanimous facts…. ….For when I look at these various anti-Christian truths, I simply discover that none of them are true.’[4] One or two points alone may not convince a person, but as one looks closely and the evidence begins to add up, the case for faith becomes stronger.


Faith and empirical knowledge, faith and logical reasoning are not at odds with each other. They are distinct and legitimate paths to seeking truth. Religious faith and natural faith maintain the same internal logic: holding something for true that we ourselves do not see or deduce because we trust the messenger. That is reasonable.

Faith requires trust in another person, and as such, moves beyond a merely rational process, but it is not irrational.

Do you believe me?

Fr. John Bullock, LC


Photo by Zac Durant on Unsplash

[1] Cf. Josef Pieper, ‘Was heist Glauben? Grünewald Sprechkassenten, 1998, Hörbuch, ISBNÑ 978-3-7867-2089-8;


[3] Cf. Compendium of the Catechism of the Catholic Church. Washington DC: United States Conference of Catholic Bishops. 2005 , n. 3.

[4] Orthodoxy (Chesterton, G. K., 95-96)

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