Common Questions

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

Q2: Doesn’t Evolution show that a “Creator” is not needed?

No. Evolution and Creation are not competing ideas. They answer different questions.

Cosmic evolution and biological evolution describe how the universe itself and the living things within it change over the course of time.

Creation is the reason why there is a universe at all.  God causes the universe to exist. In the words of St. Thomas Aquinas, “God is to all things the cause of being.” 1

An analogy might help to make the distinction clearer.  In the plot of a novel, one thing leads to another in chains of cause and effect.  But none of those things happening within the novel’s plot explains why there is a novel at all.  There is a novel only because the novel’s author conceived of it in his or her mind.  The evolutionary processes going on within the universe are analogous to the chains of cause and effect going on within a novel’s plot, whereas God’s Creation of the universe is analogous to the author thinking up the novel and its plot.

This analogy allows us to see why it makes no sense to be asked to choose between Creation and Evolution.  It is like being asked whether a particular event in a novel’s plot is caused by other events in the plot or by the author coming up with the novel and its plot.  To make this more concrete, consider J.R.R Tolkien’s novel The Hobbit. In it, the character Bard the Bowman kills the dragon Smaug with an arrow.  What if someone asked you whether the dragon died because the bowman shot him or because Tolkien wrote the book that way?  That would be an absurd choice to have to make, for obviously both statements are true. The bowman shooting the arrow is the cause within the story of the dragon’s death, whereas Tolkien is the cause of the story itself and therefore of everything that happens in it.

Similarly, we could ask about any species of animal — say the hippopotamus — whether it arose through a gradual process of evolution from earlier species, or because God willed a universe to exist that has that plot.  The answer is both.  The first answer is at the level of cause and effect within nature’s plot — i.e. the level of natural science.  The second answer is at the level of the ultimate “cause of being” — i.e. the level of the theology of Creation.

Catholic theology calls the causes within the created world (i.e. within its plot) “secondary causes,” and it calls God, who causes the world to be, the “Primary Cause.”


1.. St. Thomas Aquinas, Summa Contra  Gentiles, Book 2, chapter 15.

Resources for further study

Primary and secondary causality:

Catechism of the Catholic Church, sections 306-8, 323.

Faith, Science, and Reason: Theology on the Cutting Edge (2nd edition), Christopher T. Baglow (Midwest Theological Forum, 2019) Chapter 3, pp. 52-58

Michael W. Tkacz, “Aquinas vs. Intelligent Design,” the three consecutive sections entitled  “An Earlier Creation Crisis,” “Out of Nothing at All,” and “Take the Hippo, For Example.”

Science and Religion. Lawrence Principe. The Great Courses, 2006. Lecture 4.

“Bridging a False Divide.” Bishop Robert Barron. First Things, April, 2014.

The God of Faith and Reason: Foundations of Christian Theology. Robert Sokolowski. (The Catholic University of America Press, 1995. Chapters 1-4.

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