‘From the Ether to the Quantum Field’ is an essay in which I retrace the scientific development of the notion of the ether, as it dominated 19th century science, to the notion of the quantum field that is the final answer of modern science to the cosmic energy field as well as the human biofield that various researchers have detected and described, and that they all termed differently. Because of the terminological confusion, it was not obvious that all those researchers, from Carl Jung to Harold Saxton Burr, were actually talking about one and the same thing.