Continental philosophy is a retrospective, primarily Anglo-American label rather than a self-description used by any of the thinkers it groups together, so there is no founding text, school or manifesto scholars point to as its starting point the way historians point to Husserl's Logical Investigations for phenomenology or Frege's Begriffsschrift for analytic philosophy.
What would resolve this A settled historiographic consensus on whether the category names a real shared tradition with an identifiable origin or only a boundary drawn retrospectively from the analytic side of a later disciplinary split; historians of philosophy, not philosophers working within either tradition, would have to establish it.
OpenHistory of philosophy / philosophical historiographyStanford Encyclopedia of Philosophy