MR quotes Carl Sagan (one of my heroes, back in the day): The question there is what the word 'spirituality' is supposed to mean. It's clear that Sagan isn't using it in the ancient sense of 'touched by the holy spirit'. He seems to be using the word in the modern sense, where it refers to an emotion. Specifically to the kind of subjectively exalted emotion that religious people have felt when contemplating God. Sagan's saying that he thinks that one can feel the same kind of emotion when contemplating the universe. I think that's true. We seem pretty small when imagined in a frame that large. Many people have felt nothing more than insignificance when they think that way. Many people recoil away from it in horror. So what makes Sagan's cosmic vision so fulfilling to him? That's the question. My own sense is that astronomy kind of stimulated Sagan's personal religiosity. Astronomy was almost a substitute church for him. But what was it about astronomy that justified that? Contemplating the scale and the intricacy of the universe is beautiful to Sagan and it gives him a soaring feeling. He's elated. But why? What is it about big and complicated that feeds the same kind of emotion in Sagan that contemplating God does in others? Put in terms of the subject line of this thread -- a mechanistic clock-work might be big and intricate too. It might even be beautiful in a way. But where does all the spiritual elation come from? Obviously I never knew Sagan personally and never had the opportunity to talk to him. But my guess is that he felt, perhaps in some unspoken way, that the astronomical universe contained a mystery. A mystery that, if he could only penetrate it, would pay off for finite human beings like him in the same way that faith in God is supposed to pay off in the lives of religious believers. In a sense, I think that Sagan's elation at doing astronomy was his own personal version of what other people would call the search for the divine. In other words, for all of Sagan's avowed atheism, it was his religious quest. I have come around to the view that Sagan was a highly religious person, albeit religious in a highly personal and unorthodox way. It remains an open question whether his imagining the universe almost pantheistically, as if the immensity of the universe was somehow divine, was justified. (And if so, how.) That's basically the question of this thread, and in my opinion it's a valid and an important question in the philosophy of religion.