Why do we call cinema The Seventh Art?

Solution 1:

Hegel first classified five arts in Lectures on Aesthetics:

  1. Architecture
  2. Sculpture
  3. Painting
  4. Music
  5. Poetry

In 1911, Ricciotto Canudo wrote The Birth of the Sixth Art arguing that Cinema was #6; later he redefined dance as #6, making cinema the seventh art.

The term is much more common in French than in English today.