While Clarke made his point very well in his fiction - and I
  *do* love his fiction, I like Sagan because he successfully taps
  into what they call the "religious centers" of the brain - that
  sense of Awe and Wonder and applies it to whatever it is that
  *he personally* was in awe and wonder about.

  Sagan's agenda was anti-fraud but pro-human... one of the last
  great Humanists.