|A cartoon (Ѻ) visual of physicalism, which denies afterlife, vs dualism, which allows for soul and afterlife.|
German physicist Hermann Helmholtz’s 1847 memoir “On the Conservation of Force”, in which he overthrew the concept of vital forces, is said mark the initiation of modern physicalism. 
The following are related quotes:
“Physicalism is a kind of monism, opposing the dualist’s distinction between two kinds of substance: matter and mind. As such, it is descended from ‘materialism’: the view that everything is matter—for instance, the view that nothing exists but collections of atoms in the void—as opposed to say Cartesian dualism, which held that as well as matter (extended substance) there is also mind (thinking substance).”— Tim Crane (1990), “There is No Question of Physicalism” (pgs. 185-86) 
● Physico-chemical materialism
1. Russell, Bertrand. (1946). “Mind and Matter in Modern Science”, The Rationalist Annual, Watts & Company; in: Bertrand Russell on God and Religion (chapter 11, pgs. 151-63; definition, pg. 151), ed. Al Seckel, Prometheus Books, 1986.
2. Papineau, David. (2005). “The Rise of Physicalism” (pdf), Kings College London.
3. Crane, Tim and Mellor, D.H. (1990). “There is No Question of Physicalism” (pdf), Mind, 99:185-206.
● Physicalism – Wikipedia.