IN THE SECOND encyclical of his papacy, Pope Francis draws on the legacy of his namesake, Francis of Assisi, who has been described as ‘one of the most attractive and best-loved saints of all time’, to make a case for a Christian imperative to care for the earth, a common home to all God's creatures. When Saint Francis saw the marvels of animals or the beauty of natural phenomena, his instinctive reaction was one of song, an act of praise for the Creator. Song and sound are central to this saint's expression of praise in the medieval story of his life, and this theme is evident in the number of his encounters with noisy animals and birds. His human interaction with animal sound offers sometimes contradictory models for the purpose of vocal expression, which nevertheless set a precedent for Christian thinking across the ages. In narratives of his Life from the Middle Ages, sound and silence are set against a backdrop of religious and literary reform, and a new model of mendicancy in which the saint moves through different soundscapes to preach to the people and creatures there present, many of which are already expressing praise in their own, sometimes instinctive, ways. As Pope Francis highlights in his encyclical, in a number of instances inspired by models from early hagiography, Saint Francis observes the instinctive praise of different creatures. However, his interactions with them also demonstrate that he has a vital role to play in directing their praise to a different level of existence.

The story of Francis of Assisi has been considered by some scholars as an early precursor to Western environmental thought. His environmental and ecological associations have been a growing focus of his cult since he became patron saint of ecologists in 1990.