Catholic dogma on the 'certainty of knowing God' question


Ludwig Ott, “Fundamentals of Catholic Dogma”. A very commonly used resource in Catholic circles on the dogmas and doctrines of the Catholic Church and their sources and supporting materials.


What is the point of faith if that statement was true?


It means that if reason is used properly you can attain certain knowledge of the “existence” of God. This is not the same thing as saying we can know divine revelation by reason alone however.

This is a very strong claim and if it is not true then this would be a challenge to the infallibility of the church.

Personally i agree with this claim. As far as reason can attain certainty about anything you can know that God exists as defined by his general metaphysical attributes at least…


Divine revelation is a matter of faith.


It simply means that by the light of reason alone, every man can know for certain that God exists.

The problem with your “concern” (which is really a non-concern), is that you’re already jumping the gun on systematic theology, which begins with reason before we even move on to faith. Ott hasn’t even gotten to that point yet regarding faith, or even Christ. He is only the first reasonable starting point: man’s reason and God’s existence.

You don’t have to have a Bible, or a preacher or a Church or a priest at this stage. By smarts alone, one can only reasonably deduce that there has to be a God. Nothing about Trinity, Incarnation, Jesus, Holy Spirit. At this stage in the search for knowledge, faith is not required; only reason. I only need look at my right eye to tell me this, and I don’t need a Bible or a Church.

Faith would follow as one’s reason leads one to explore this God, and as one, firm in his belief that this God exists, gets to realize that a relationship with this God will require faith at some point. But to merely deduce his existence, faith is not needed. That’s why we have folks like Deists, who just loved reason, and had to admit the existence of God, but did not proceed past that.

Which is why I’m concerned for the eternal fate of atheists, especially the hard-hearted ones. Denying the existence of a god is contrary to reason, and one would be hard-pressed to claim innocence on the “full knowledge” component of mortal sin here. Man’s impulse to recognize and seek God is hard-wired. It takes a hardened will to force oneself to deny the existence of God.


Hi, FollowChrist,

Ludwig Ott was a German theologian who wrote the definitive text on Catholic Dogma in the 1950’s. His book is still in use today.

If you’re interested, you can buy it from Amazon, or used from one of their Storefronts inexpensively.

Hope this helps!



Thanks. No, I don’t know him. I admit that I have received a few shocks glancing through a few pre Vatican II theologians here and there, 19th, 20th century. Vatican I. Just as an aside. I certainly don’t accept the certainty of knowing God through natural reason - I hope that is taken out of context. As for the shocks, I guess I can say the same for some ideas from the post Vatican II folks too. :slightly_smiling_face:


We see the world around us and reason forms an understanding of its structure - physical, psychological and ontological.

We each exist, individually as persons.

Persons exist in relation to the world and to God, the Ground of their being. We have the capacity to know the world as it truly is, in and through Christ. The world stripped of the stain of sin is one of beauty and wonder.

The other exists and we can know them through love. Loving one’s neighbour is the awareness of one humanity of persons. In Christ we are one, where in Adam we are fragmented within ourselves and as a holy community. At the Foundation of everything is Love, eternal, infinite, Triune and One.

God is Existence, is Beauty, is Love - the perfect relationship between the Father and the Son, united in the Holy Spirit, the Breath of Existence shared and becoming One in the giving.

God is everywhere and in everything.

Everyone knows this although it is buried. We have to pray and work on our relationship with God, surrendering our hearts and intellect to Him. This seems to usually happen when we realize we are getting nowhere, juggling what we know.

And in the end, its funny because we knew it all along.

It is as certain as one’s own existence.

These are not things that we think up, but rather that we know. There can be doubt of both because of the ignorance inherent in the human condition. We tend to lose ourselves in the illusions of the world.

It is in the reality that such illusions exist, but not through them that we know God.

We distance ourselves from God once ego steps in. God possesses us; we cannot posses Him. And, we may fall over and over again as a purification because we come to know God becoming Christ-like. The knowledge of God that we possess, isn’t ours per se. It is the relationship between oneself and God, developed as we travel on the Way that is Jesus Christ.


The simple answer is the autonomy of reason and revelation. Both lead to truths where the other cannot reach, and cross paths in fundamental matters.


It seems to me that we are debating whether it possible for someone to be certain God exists or not through natural reason. It seems to me this is a non isssue. Especially, if God exists and he created us to know him, then it must be at least possible for us to come to a reasonable certainty about his existence. Whether or not we have actually attained this certainty or not it would not be a stretch to imagine some already have. Look at Aristotle and Aquinas for example.

As far as having faith is concerned Christian faith is not merely concerned with belief in God’s existence, but rather supernatural faith, which comes to us from God. This is believing in God’s revealed Truth to us especially in His Son. This kind of faith is not possible through natural reason but is a supernatural gift of grace, along with supernatural love and hope.

Also, I think we can make a distinction between reasonable certainty and absolute certainty. We can for instance be reasonable certain we are not just a brain in a vat being experimented on by a mad scientist. Just because we don’t have absolute certainty doesn’t mean we need to doubt a reasonable certainty. There would be in the absence of strong evidence or a defeater argument no reason to think we are just brains in a vat.


It doesn’t take any great intellectual somersaults to become certain that there is a God.
I’ve known this one to begin a journey from certainty to certainty.

Something can’t come from nothing. Something has to come from something.

That, someone can be certain of.


Yes, faith. People apparently have faith on different things.


Yes. I’d just note that our reasoning power is, itself, further evidence of our design. And it is a gift of God, of course. I believe He gave it to us for the purpose of bolstering our faith, and in some cases, for discovering Him in the first place.
Belief in God makes one a theist. This plus belief in the Holy Trinity, in Jesus Christ and his atoning sacrifice, etc. makes one a Christian. Belief in all these and in the Church, her Sacraments and dogma, etc. makes one a Catholic Christian.
Or something like that.
I used etc. because I won’t pretend to be exhaustive, and some might add other criteria. And I know less, all the time…


This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.

DISCLAIMER: The views and opinions expressed in these forums do not necessarily reflect those of Catholic Answers. For official apologetics resources please visit