The extract "The scientific theory is concerned only with the outward and visible machinery and process.......; its account of the process may have to be considerably changed or may be dropped altogether in the light of new discovery.." is very revealing. In another extract we learn that "Other forces than hereditary variation have been at work in bringing about the appearance of new characteristics; there are physical forces such as food, light-rays and others that we are only beginning to know, there are surely others which we do not yet know; there are at work invisible life-forces and obscure psychological forces. For these subtler powers have to be admitted even in the physical evolutionary theory to account for natural selection;". I would be inclined to believe food, light-rays would fall under adaptation and selection by nature ie natural selection and therefore fit into the Darwinian scheme . However could you please expatiate on the obscure psychological forces. Would you include in it the subconscient will?