Joseph Dietzgen,
The Positive Outcome of Philosophy
“ If we refer to phenomena of sense perception as forces of matter in general, then this generalized matter is nothing but an abstract conception. But if we mean by the term sense perception the various concrete substances, then the general element which embraces the differences of things and pervades and controls them is force producing concrete effects. And whether we say matter or force, the mental which science is studying, not with its hands, but with its brain, the so-called essence, nature, cause, ideal, superior or spiritual, is the generality comprising the special things. ”
