In the undivided Church principles were laid down, chiefly by a decree of the 7th Ecumenical Council, governing an art of transfiguration, the art of the icon. The whole church, of course, its architecture, frescos and mosaics, is one enormous icon which bears the same relation to space as the unfolding of the liturgy does to time; it is ‘heaven on earth’, the manifestation of the divine-human where the flesh destined to die is transformed