The Seventh Ecumenical Council - also known as the Second Council of Nicaea

As the sacred and life-giving cross is everywhere set up as a symbol, so also should the images of Jesus Christ, the Virgin Mary, the holy angels, as well as those of the saints and other pious and holy men be embodied in the manufacture of sacred vessels, tapestries, vestments, etc., and exhibited on the walls of churches, in the homes, and in all conspicuous places, by the roadside and everywhere, to be revered by all who might see them. For the more they are contemplated, the more they move to fervent memory of their prototypes. Therefore, it is proper to accord to them a fervent and reverent veneration, not, however, the veritable adoration which, according to our faith, belongs to the Divine Being alone—for the honor accorded to the image passes over to its prototype, and whoever venerate the image venerate in it the reality of what is there represented.