Leo Ruickbie is an historian and sociologist of magic, witchcraft and Wicca. He is the author of several books, beginning with Witchcraft Out of the Shadows, a 2004 publication outlining the history of witchcraft from ancient Greece until the modern day. Ruickbie was born in Scotland and took a Master's degree in Sociology and Religion at the University of Lancaster. He then studied at King's College London and was an awarded a PhD for his thesis entitled The Re-Enchanters: Theorising Re-Enchantment and Testing for its Presence in Modern Witchcraft. On Samhain 2007 he launched Open Source Wicca, a project inspired by the Open Source software movement aimed at making the founding texts of Wicca more readily available by releasing them under a Creative Commons licence. In 2008 and 2009 he exhibited on the subject of witchcraft in France.

Witchcraft Out of the Shadows begins with a survey of historical influences from classical times, northern European paganism, and medieval and early modern Europe. It then describes the roots of modern neopagan witchcraft in groups such as the Hermetic Order of the Golden Dawn and individuals such as Aleister Crowley and Doreen Valiente. Particularly important is the critical analysis of the claims made by Gerald Gardner about Wicca, as well as a detailed discussion of the liturgical content of Gardner's Ye Bok of Ye Art Magical and its sources.

Augustine of Hippo ( /ɒˈɡʌstɨn/ or /ˈɔːɡəstɪn/;Latin: Aurelius Augustinus Hipponensis; November 13, 354 – August 28, 430), also known as Augustine, St. Augustine, St. Austin,St. Augoustinos, Blessed Augustine, or St. Augustine the Blessed, was Bishop of Hippo Regius (present-day Annaba, Algeria). He was a Latin philosopher and theologian from Roman Africa. His writings were very influential in the development of Western Christianity.

According to his contemporary, Jerome, Augustine "established anew the ancient Faith." In his early years he was heavily influenced by Manichaeism and afterward by the Neo-Platonism of Plotinus. After his conversion to Christianity and baptism in AD 387, Augustine developed his own approach to philosophy and theology, accommodating a variety of methods and different perspectives. He believed that the grace of Christ was indispensable to human freedom, and he framed the concepts of original sin and just war.

When the Western Roman Empire was starting to disintegrate, Augustine developed the concept of the Catholic Church as a spiritual City of God (in a book of the same name), distinct from the material Earthly City. His thoughts profoundly influenced the medieval worldview. Augustine's City of God was closely identified with the Church, the community that worshipped God.