The Catholic Book Club discussion

5. What is real and Unreal, in the way Dr. Esolen uses those terms.

Real is anything grounded in God, the ultimate Truth. Unreal is any lesser thing that tries to assume God's place, e.g. idolatry.
But of course that's circular reasoning if someone doesn't accept the starting point but rather asserts that only what's knowable/quantifiable/verifiable with the senses (or "science") is real, or that there is no objective reality at all, only what an individual prefers. He points out the self-contradiction in those positions too.