John William Dunne Quote

Now, when we say of any occurrence that it is 'physical', we mean thereby that it is potentially describable in physical terms. (Otherwise the expression would be wholly meaningless.) So it is perfectly correct, to state that, in every happening with which our sensory nerves are associated, we find, after we have abstracted therefrom every known or imaginable physical component, certain categorically nonphysical residue.

p. 5 - An Experiment with Time (1927)