Les énigmes de l'Univers

by Ernst Haeckel

"Les énigmes de l'Univers" by Ernst Haeckel is a philosophical work of scientific popularization published in 1899. Haeckel responds to the claim that science faces unsolvable mysteries by championing scientific optimism and monism—the doctrine of nature's fundamental unity. He argues that scientific progress, particularly evolutionary theory, continuously reduces the universe's enigmas and displaces religious and metaphysical explanations. Central to his philosophy is the "law of substance," which synthesizes the conservation of energy and matter to provide a materialist explanation of the cosmos.