Every summer, since 1996, I have lectured at Summit Ministries  in Manitou Springs, Colorado, at the foot of Pike’s Peak. It is a two-week summer camp for Christian young men and women between the ages of 16 and 22. During those two weeks, students listen to lectures from professor-types like me, engage in a variety of physical activities (e.g., hiking, sports), pray, read Scripture, and meet in small groups with other students. It’s quite an operation, and I am honored to be part of it. This summer, I have already spoken at three of the two-week sessions, with two more engagements remaining in August.
One of my talks, “Five Campus Dogmas,” a lecture I’ve been giving at Summit for the past three years, deals with the sorts of assumptions – rather than explicit beliefs – that a Christian student is likely to encounter. but not necessarily discern, attending a secular college or university. So, what we cover are not direct critiques of Christian faith, but philosophical assumptions that often bypass the critical faculties and subtly weaken belief.
The thing I most like about this lecture is that it affords me the opportunity to introduce the students to the joys of philosophical reasoning and why so many great Christian minds throughout history – including St. Augustine, St. Anselm, St. Bonaventure, St. Thomas Aquinas, C.S. Lewis, St. Pope John Paul II, and Alvin Plantinga – saw (and see) in this enterprise a way of thinking that is both congenial and supportive to their exposition of the Gospel.
One of the five campus dogmas we cover is the belief that all that exists is the physical world. Often called materialism, it is the view that everything in the universe – including you, me, the dog, the park bench, and the planet Jupiter – is ultimately reducible to matter.
I do not offer the students a conventional critique, such as a cosmological argument for God’s existence, which, if successful, shows that there exists a non-physical, transcendent, necessary being on which all contingent reality exists, and thus materialism is mistaken. Rather than point to the universe outside them, what I do is aim for the universe within them, showing that much of what they take for granted in terms of their mental lives is seemingly inexplicable under materialism. Among the several examples I provide is a lovely argument offered by the Dominican Friar, Fr. Thomas Crean, found in his book, God is No Delusion: A Refutation of Richard Dawkins . 
The most intriguing of the several arguments presented by Fr. Crean begins with this question, “What is ultimate, mind or matter?”
First, he asks us to consider necessary truths. What are those? He writes: “Something that is not dependent on chance or human choice, but which has to be the case,” such as “the proposition that the circumference of a circle is equal to twice its radius multiplied by π.”
Second, there are several things we can say about this proposition:
- It does not depend on the material world. For, Fr. Crean explains, “material things are subject to this law; they don’t create it. The circular cross-section of a tree trunk. . .does not cause it to be the case that the circumference of any circle will equal 2πr.”
- Thus, he concludes, “necessary truths are independent of the material objects that they govern. If there had never been a material universe, it would still have been true that the circumference of any possible circle will equal twice its own radius multiplied by π.”
- But if a necessary truth does not depend on the material universe, where is it if the material universe does not exist? In a mind, since it is an abstract object and abstract objects require minds.
- “So,” writes Fr. Crean, “if we agree that certain things are true independently of material things, we must admit that at least one mind exists independently of material things.”
Another dogma I cover is this claim: because of the explanatory power of Darwinian evolution in accounting for biological change over time, it is no longer intellectually respectable to believe that the universe’s apparent design can be attributed to God. As I point out to the students, the problem with this view is that it assumes that divine action is in competition with scientific theories.
So, if a theory, such as Darwinian evolution, can account for increased complexity of biological organisms, God is superfluous. Unfortunately, some Christians buy into this mistaken view of divine action and eventually abandon their faith, since the “God” in which they believe “exists” at the mercy of scientific impotence. To quote the Hulk in the recent Avengers film, “Puny god .” (Thanks to Ed Feser  for giving me that one).
On the classical view of God – the one embraced by virtually all serious Christians, Jews, and Muslims until very recently – the universe’s intelligibility as a whole requires his existence. Thus, Darwinian evolution can never, in principle, displace God’s creative power, since contingent reality itself, including the entire Darwinian scheme, points to something beyond itself. Think about it: all scientific theories – even those that appeal to chance – presuppose order. For example, natural selection, the engine of Darwinian evolution, cannot even get off the ground without pre-existing laws and the apparent striving of organisms to some natural end.
My approach to the Summit students has been, for quite some time, shaped by the words of C. S. Lewis: “To be ignorant and simple now – not to be able to meet the enemies on their own ground – would be to throw down our weapons, and betray our uneducated brethren who have, under God, no defense but us against the intellectual attacks of the heathen. Good philosophy must exist, if for no other reason, because bad philosophy needs to be answered.”