As reproduced on the church's official Chapter XII page (observed 2026), Eddy's text states that disease is a false belief of "mortal mind, alias matter," with no reality of its own; rising in the conscious strength of the spirit of Truth to overthrow that belief, against the supremacy of Spirit, dissolves the disease along with it.
Eddy’s proposed mechanism, stated in her own text at the same locator that names cancer, consumption, and smallpox (Science and Health, SH 390:27-391:6) and echoed in the book’s generic-sickness passages (1:1-1:3; 14:12-18): disease is a belief of “mortal mind, alias matter” opposed to “the supremacy of Spirit,” dissolved by rising in the conscious strength of “the spirit of Truth.” This is Eddy’s own proposed, doctrinal explanation, attributed to these texts alone — not demonstrated physiology, not a demonstrated cure.
Appears in
Sources
- Science and Health, with Key to the Scriptures (Project Gutenberg eBook #3458) — Eddy, Mary Baker. Science and Health with Key to the Scriptures. Project Gutenberg eBook #3458, transcribed by Dave Keyston. Release date 1 October 2002; most recently updated 8 January 2021.
- Science and Health, Chapter XII: Christian Science Practice (christianscience.com) — The First Church of Christ, Scientist. Chapter XII: Christian Science Practice. Science and Health with Key to the Scriptures, official online edition, christianscience.com. Accessed 2026.