Thomas Aquinas

## Thomas Aquinas Thomas Aquinas

**Thomas Aquinas** (1225-1274) was a Dominican friar and theologian whose *Summa Theologica* and other works established him as one of the greatest philosophers and theologians of the Catholic Church, and to whom several alchemical treatises were falsely attributed in the late Middle Ages and Renaissance. The historical Aquinas wrote extensively on philosophy, theology, and natural philosophy, synthesizing Aristotelian philosophy with Christian doctrine and addressing questions about the nature of matter, causation, and the possibility of transformation. In his authentic works, Aquinas discussed the theoretical possibility of alchemical transmutation in the context of Aristotelian natural philosophy, arguing that if alchemists could truly replicate the natural processes by which metals are generated in the earth, transmutation would be possible, but expressing skepticism about whether the art had actually achieved this.

The alchemical texts attributed to Aquinas include the *Tractatus de esse et essentia mineralium* (Treatise on the Being and Essence of Minerals), the *Thesaurus alchemiae* (Treasury of Alchemy), and the *Secretum secretorum* (Secret of Secrets, not to be confused with the pseudo-Aristotelian text of the same name). These works present detailed alchemical theory and practice, discuss the preparation of the Philosopher's Stone, and claim Aquinas's authority for the reality and possibility of transmutation. The attribution of alchemical works to Aquinas—the "Angelic Doctor" and one of the Church's greatest authorities—gave them enormous prestige and helped to legitimize alchemy within Christian intellectual culture.

Modern scholarship has definitively established that the alchemical texts attributed to Aquinas are spurious, likely composed in the fourteenth or fifteenth centuries. Nevertheless, the question of why Aquinas became a target for alchemical attribution is interesting: his genuine discussions of transmutation's theoretical possibility, his status as a supreme philosophical authority, and his Dominican affiliation (linking him to Albertus Magnus, another figure to whom alchemical texts were attributed) made him an attractive candidate. The pseudo-Thomistic alchemical corpus represents the desire to claim the highest intellectual and religious authority for alchemy, and the ways in which alchemical literature created its own canon of authoritative voices. Thomas Aquinas thus exemplifies how even figures who wrote skeptically about alchemy could be posthumously transformed into alchemical authorities through the attribution of practical texts that claimed their support for the art.

---