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.