Calian 2010, p. 184: "In several works he used alchemical principles and symbols without hesitation to demonstrate theological realities. Borrowing alchemical terminology in order to explain religious and mystical frameworks, Böhme assumed that alchemical language is not only a metaphor for laboratory research. Alchemy is a metaphysical science because he understood that matter is contaminated with spirit." Calian, George-Florin (2010). Alkimia Operativa and Alkimia Speculativa: Some Modern Controversies on the Historiography of Alchemy. Annual of Medieval Studies at CEU.
Mundik 2016, p. 32. Mundik, Petra (2016). A Bloody and Barbarous God: The Metaphysics of Cormac McCarthy. University of New Mexico Press. ISBN978-0826356710.
Faivre 2000, p. 28. Faivre, Antoine (2000). Theosophy, Imagination, Tradition: Studies in Western Esotericism. Albany, NY: State University of New York Press. ISBN0-7914-4435-X. OCLC41944660.
Faivre 2000, p. 13. Faivre, Antoine (2000). Theosophy, Imagination, Tradition: Studies in Western Esotericism. Albany, NY: State University of New York Press. ISBN0-7914-4435-X. OCLC41944660.