In 1866 the German zoologist Ernst Haeckel defined a new science in his work Generelle Morphologie der Organismen. He called it Oecologie: “die gesammte Wissenschaft von den Beziehungen des Organismus zur umgebenden Aussenwelt”. It was the whole science of the relations of an organism to the world around it.
Haeckel counted all the conditions of existence among these relations, in the wider sense. The Federal Environment Agency lists his definition in its chronicle of environmental history under the year 1866.