Merry Cosmos - 

Notice how Sagan emphasizes the incredible and incomprehensible vastness and immensity of the universe?  And how he offers a prophetic insight that "the sky is calling?"

Atheist though he was, he was also - as a rational human being - what a Thomist would call an "intellector of being." Therefore, he was an "intellector of the good" since "good" and "being" are interchangeable.

As the human mind expands up to contemplate the very large or down to contemplate the very small, particular beings dissolve and the mind begins to obtain a concept of Being itself, which is Goodness, which is the reason that we feel a giddy euphoria from contemplating the large, whether it is "billions and billions of stars" or the Cosmos or God.

Sagan couldn't help himself from scratching on the door of theology.  He, like all of us, are wired that way.