Common Questions

Frequently asked questions about the relationship between science and the Catholic faith.

Q9: Isn’t the idea of “faith” contrary to reason, evidence, and freedom of thought, which form the basis of science?

No.  Even in non-religious matters, our knowledge has two sources: what we learn by our own observations and reasoning, and what we learn from others.  It is true that we could — in principle — verify for ourselves much of what we learn from others, if we had the necessary time and resources.  In practice, however, the vast majority of what any person knows depends to some extent on the word of others.  Because it is necessary to rely on the word of others in many things, it cannot be irrational to do so.  Indeed, it would be irrational never to do so.

Moreover, some things can only be known in this way.  For example, we cannot know the thoughts of another person, unless the person chooses to reveal them to us.  And we cannot know the person himself or herself, except superficially, without such self-revelation.  Christians and Jews believe that God has revealed himself and truths about himself to the human race so that human beings can live in proper relationship to him and ultimately have a share in the divine life.

As the Catechism of the Catholic Church says,

“Trusting in God and cleaving to the truths he has revealed is contrary neither to human freedom nor to human reason. Even in human relations it is not contrary to our dignity to believe what other persons tell us about themselves and their intentions, or to trust their promises (for example, when a man and a woman marry) to share a communion of life with one another. If this is so, still less is it contrary to our dignity to yield by faith the full submission of. . . intellect and will to God who reveals, and to share in an interior communion with him.” (CCC 154)

Reason does not forbid but rather requires that we believe what God has revealed, because God cannot deceive.1 The question for human reason is whether we have a sufficient rational basis for believing that God exists, that he has revealed himself to humanity, and that we can identify where that revelation is to be found.  Catholics believe that there are such rational grounds, both philosophical and historical.2

“Faith” is believing in what God has revealed. According to Christian understanding, this requires an interior disposition that is a gift from God, who opens our minds and hearts to his revelation and illuminates our understanding.3

Both faith and reason require freedom.  Freedom is necessary both in seeking the truth and in genuinely assenting to it.  It is not contrary to this freedom for the human mind to submit to a truth once it has discovered it.  The scientist, for example, submits to the “data” of experiment.  (“Data” means “what is given.”)  In a somewhat analogous way, the faithful Christian submits to what theologians call the “data of revelation.”  The scientist submits to what nature reveals; the Christian submits to what God has revealed  — and also to what nature reveals.  Accepting such truths, far from being contrary to reason, opens new territory for human reason to explore and new questions for it to investigate, and thus extends the reach of reason.

In the famous words of Pope St. John Paul II: “Faith and reason are like two wings on which the human spirit rises to the contemplation of truth; and God has placed in the human heart a desire to know the truth — in a word, to know himself … .” 4


1.. First Vatican Council, Dogmatic Constitution on the Catholic Faith,  Chapter 3, “On Faith”, article 2.

2.. First Vatican Council, Dogmatic Constitution on the Catholic Faith,  Chapter 3, “On Faith”, articles 4, 10 and 12.

3.. First Vatican Council, Dogmatic Constitution on the Catholic Faith,  Chapter 3, “On Faith”, articles 2, 6-7.

4..  Encyclical letter Fides et ratio, St. John Paul II, first sentence.

Resources for further study

Catechism of the Catholic Church, Part I, Section I, Chapter 3.

Encyclical letter Fides et ratio, St. John Paul II.

Faith, Science, and Reason: Theology on the Cutting Edge (2nd edition), Christopher T. Baglow (Midwest Theological Forum, 2019), Chapter 1.

Science and Religion. Lawrence Principe. The Great Courses, 2006. Lecture 3.

Thomistic Evolution: A Catholic Approach to Understanding Evolution in the Light of Faith, Nicanor Austriaco, James Brent, Thomas Davenport and John Baptist Ku, (Tacoma, WA: Cluny Media LLC, 2016), Chapter 1-4.

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