It is of first-class importance that our answer to the Riddle of the Sphinx should be in step with how we conduct our civilisation, and this should in turn be in step with the actual workings of living systems.
The Polar Express is about faith, and the power of imagination to sustain faith. It's also about the desire to reside in a world where magic can happen, the kind of world we all believed in as children, but one that disappears as we grow older.