For a long time I have felt that presuppositional apologetics and classic apologetics, when done and held rightly, can be mutually supporting. Presuppositions feed facts. But facts, the way the world is, feed our presuppositions as well. While Schaeffer does not use this exact terminology that is part of the lesson I learned from this book.
I found this book more difficult than Escape from Reason and for some reason I skipped The God Who is There, which I will have to pick up. Schaeffer outlines how the failure to have an infinite personal God who speaks leads inevitably to meaninglessness. But more than that he shows how an infinite personal God who created this world and who speaks is the only option that matches the facts of how the world actually is. The key fits the lock and only this key fits the lock.
A couple of other thoughts. Schaeffer writes with a high level of empathy for the modern man in the book. Modern man is alienated, living in a meaningless world with no way of knowing what is true and what is false, what is good and what is evil, what is real and what is imaginary. Schaeffer had an answer for this lostness. But he does not just have an answer he truly loves those he speaks to.
Second, Schaeffer (along with Os Guinness) has made less afraid of questions. Schaeffer noted that at L’Abri no question was off limits. Anything could be asked and there was answer for it from the Bible and the Christian worldview. A lot of times men steeped in presuppositional apologetics, like myself, simply say to objections, “Well you just need to believe.” Yes they do, but they also need answers. And Christianity has those answers.