An 18th-century Anglican cleric and theologian whose methodical approach to holiness and small-group accountability influences Foster's exploration of spiritual practices, emphasizing communal growth and practical faith.

A medieval figure known for his lifestyle of simplicity, poverty, and service, serving as an example of how spiritual disciplines like simplicity and service can transform daily living and enhance worship of God within creation.

Spiritual pioneers of the 17th century who emphasized the "Inner Light" and direct communion with the Holy Spirit, their practices of silence and simplicity inform Foster’s approach to spiritual disciplines and communal discernment.