Tony, I speak from your side of the argument. In the spirit of your statement above, we atheists should have the intellectual honesty to acknowledge when something is a real problem for us. The existential Leibniz question in your article title (which, by the way, you haven’t answered) is precisely the crucial problem for the scientific world view.

Science rests on the notion of causality. What caused the universe? The Big Bang. What caused the Big Bang? Quantum fluctuations, you say? OK, what caused the quantum fluctuations? Why are there quanta? Why is there a quantum field? Causality is an infinite regress: every answer immediately poses the next question, and turtles. Even the child understands this who asks, “If God made the world, who made God?” Science cannot, in principle, get us any closer to the ultimate question, why does existence exist?

This is not to say the theists have it right. Theistic conceptions of the Big Guy in the Sky or the Great Cosmic Mind are childish twaddle, just semantic band-aids over the very real, deep problem of the Existential Question. We need to acknowledge the limitations of our method. However far we may push the boundaries of our understanding, there remains a Truth Beyond Understanding that lies forever outside our grasp.