The Amphitheatrum Sapientiae Aeternae owes its long life less to its Latin, a dense weave of scripture, cabala and Paracelsian alchemy, than to its plates, and to one plate above all: the alchemist's laboratory-oratory. The engraving shows a single vaulted room; at the left the adept kneels in a tented oratory before an altar of books, at the right stand the furnace and vessels of the laboratory, musical instruments lie on the central table with a motto that sacred music disperses sadness and evil spirits, and across the scene runs the doctrine in a sentence: ora et labora, pray and work, the two halves of one art in one room. It is the definitive visual statement of alchemy as spiritual discipline, endlessly reproduced wherever that thesis is argued, and its companion plates, the cosmic rose, the hermaphroditic Rebis, the emerald tablet mountain, gave later theosophy and Rosicrucianism much of their imagery.
The book had a stranger administrative afterlife. Issued in part at Hamburg in 1595 and completed posthumously at Hanau in 1609, it circulated for a generation before the theology faculty of the Sorbonne formally censured it in 1625 as impious and dangerous, a condemnation that, as such condemnations do, preserved its notoriety. Khunrath himself died poor in 1605; his room with the altar and the furnace became the standard portrait of the art he practised, and of the claim that its true work was on the worker.