Finding a model or paradigm to capture the essence of light, is an enterprise of historic legend. The two main contenders,
particle beams and waves have alternated in acceptance, with each ultimately proving unsatisfactory. Currently, the particle
variant is predominant, but with strong caveats encompassed in Bohr's Principle of Complementarity. Herein a
study of correlated pairs of photons is presented. It reveals additional challenges for the particle paradigm. Finally, it is
suggested that as neither of these two paradigms is optimal, the direct-interaction paradigm as originally introduced by
Schwarzschild deserves further consideration.