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The Need for Both Faith and Reason in the Practice of Science


Albertus Magnus, patron saint of scientists, on the ceiling of Santa Maria dell’Anima, Rome.

How should a Catholic think about the scientific discoveries, theories and uses that almost dominate contemporary culture? For some, science has such a sacred aura that any scientific report is accepted with a kind of false faith as “Gospel” truth. For others, science seems only to promote ideas that challenge belief in God, the spiritual nature of man, and the sanctity of human life. There is a need for proper scientific investigations using right reason based on Western scientific methodology that relies on holy faith in God, and that, in good conscience, follows Magisterial teachings, not violating the revealed truths of the Catholic Church.

So should we label science evil simply because a small number of scientific efforts violate the fifth commandment, thou shall not kill? Without question, murder of the innocent is intrinsically evil and cannot be justified by claiming that good comes from the evil. The reality though is that the majority of scientific efforts does not lead to murder, or violate the teachings of the Catholic Church. If we look at any method or practice we can find instances of abuse or misuse. For example, a heinous activity can come to be wrongly portrayed in the media as a common practice, when in fact it is very rare. A case in point is how the media can report some type of extremist behavior among a small group of people in an organized religion and give the impression that the religion, itself, nurtures this type of behavior among its members, when in fact it does not. Therefore, it is no more logical to say that science is evil than it is to say that organized religions are evil, if immoral activities in both are promulgated by only a few in the group.

Now, the importance of faith cannot be understated. However, faith alone can lead to fanaticism. Faith without reason defies the logic that is inherent in the creation of Earth by God. The misinterpretation of “faith alone” abounds in the practice of believing something is true without evidence. Notice that in scripture, James 2:24, tells us, “See how a person is justified by works and not by faith alone.” In our works then, we must be just. Reason, as well as faith, is used in the investigation process for canonization of the known Saints. Clearly we are to draw grace from the eternal wellspring of the Holy Spirit from our faith in God, not faith in science. We cannot have faith in science; instead, we must do good works, conscientiously practice science having faith in God. Scientists who promote theories as though they are facts exhibit backwards thinking, having faith in their theories as they forget the very reason why they are theorizing, to uncover God’s true design of the universe, and thus fail to use right reason.

So, the importance of reason is clear, but reason alone potentially can lead to agnosticism. As an example, in Dante’s Inferno, Virgil takes Dante to the first plane of Hell, where he meets thinkers who were thought to be great by some throughout history. Dante asks Virgil essentially why these thinkers are in Hell. Virgil’s answer alludes to the idea that the limit of reason alone is the first plane of Hell. Yes, the highest plane of Hell, but as one might imagine, Hell is still Hell. Reason alone is not enough to reach the pearly gates of Heaven. In this regard, we cannot simply use reason to practice works of science, for reason alone can be without conscience, without faith, without the love of God. To see the face of God in eternity, we must reason to know Him, learn to love Him, and have faith to serve Him.

Does the risk of pursuing either faith or reason alone mean that we had better avoid reason in favor of faith and ignore the reasoned approach to practicing science? Pope John Paul II attempts to answer this Catholic concern quoting the Book of Proverbs cf. 16:9 in Fides et Ratio Chapter II 16,17:

“The human mind plans the way, but the Lord directs the steps” (16:9)… Therefore, reason and faith cannot be separated without diminishing the capacity of men and women to know themselves, the world and God in an appropriate way. There is thus no reason for competition of any kind between reason and faith: each contains the other, and each has its own scope for action.

Clearly, we need both faith and reason in the practice of science. St. Thomas Aquinas, the greatest Catholic theologian, used reason to explain and justify faith, often against his very own counter arguments in the truest sense of academic freedom ever expressed. Even in his revealed understanding of science.

So then, what is science? Science is the study of the natural universe. We know that God created the Heavens and the Earth. Therefore, God created the laws by which the natural Universe exist and take action. Science is merely the study of the natural universe, therefore, a study of God’s creation and thus an attempt to understand God. In its inherent Western Christian nature, science is good. Part of our existence on earth, as St. Thomas Aquinas explains in a mind and body within a soul, is to climb up Jacob’s ladder to Heaven on the two interspersed rungs: divine faith and natural reason. Both holy faith and right reason are needed to become truth-filled knowers of science and thus knowers of God.


Paul Keough holds a doctorate in biochemistry from Northwestern University. Paul writes and speaks on crucial topics at the crossroads of science and Christianity, such as bioethics, and can be reached

Fides et Ratio, St. John Paul II
The Faith and Reason Institute,Washington, D.C.
Photo of Albertus Magnus painting, Lawrence OP

Originally published April 22, 2022.