Quick: What's halfway between 1 and 9? According to a recent study, most little kids will answer "3," as will many people in non-literate cultures. And as it turns out, there's a solid evolutionary reason why that guess makes sense.
Laymen need not be afraid to read The Purposeful Universe even if they are not predisposed to science. As deep and challenging of a read as this book might be for the Average Joe, it's well worth the effort.