It is easy to associate Fervor with the drive and Catharsis with desire.  Catharsis aim at a not-yet, an ultimate payoff.  Fervor kicks down the old, the weak, renounces.   If we strip away the mountains of technical language one can employ for these things:  Catharsis makes its way to the sexual act, while Fervor consummates and finishes.   Fervor desacralizes, rapacious and cruel, but no less true.  Fervor: to be finished.    And thereby to be freed from a mandate, available to new horizons