The central principle underpinning much of Appia's work is that artistic unity is the primary function of the director and the designer.
Appia maintained that two dimensional set painting and the performance dynamics it created, was the major cause of production disunity in his time.
He advocated synchronicity of sound, light and movement in his productions of Wagner's operas and he tried to integrate corps of actors with the rhythms and moods of the music.
For Appia and for his productions, the mise-en-scène and the totality or unity of the performance experience was primary and he believed that these elements drove movement and initiated action more than anything else (Johnston, 1972).
Appia's designs and theories went on to inspire many other theatre creators such as Edward Gordon Craig, Jacques Copeau and Wieland Wagner.