Haeckel founds the Monist League; CCWV.LIFE

In 1906 Ernst Haeckel, the German zoologist who coined the word ecology and preached evolution as a religion of nature, founds the Monist League at Jena to organize his followers. Haeckel's monism, one substance under the names of God and nature alike, is naturalism in its most religious temper, with congregations, and it spreads across Germany before the war.

Tagged: Naturalism

The Event

Date: 1906 (exact)
Era: The Darwinian Century; Standard periodization of naturalist history
Location: Jena; today Jena, Germany
Traditions: Naturalism
Streams: Naturalism
Key figures: Ernst Haeckel
Key texts: The Riddle of the Universe

How the Tradition Tells It

Haeckel's monism kept a religious temper many naturalists reject; the record states his own framing, and later naturalism's distance from it is part of its story.

Primary Sources

The founding documents of the Monistenbund, Jena, 1906.

Secondary Sources

De Caro, Mario, and David Macarthur, eds. Naturalism in Question. Cambridge, MA: Harvard University Press, 2004.
Gregory, Frederick. Scientific Materialism in Nineteenth Century Germany. Dordrecht: Reidel, 1977.
Papineau, David. Philosophical Naturalism. Oxford: Blackwell, 1993.

Provenance: HIST-1410; confidence 0.95; accessed 2026-10-30.