A Revealing Question

I asked a friend (who is a Christian) recently, "Why don't you believe in the doctrine of transubstantiation?" (This is roughly the idea that the communion bread and wine actually transform into the literal body and blood of Christ.) His answer? Because he distrusts Catholic theology. Why? Because it is superstitious and has been proven false on numerous occasions by science.

This answer reveals something critical about his worldview. Any guesses as to what I'm talking about?