The barbarian, when he speaks of a spirit, attaches at least some sense
to this word; he understands by it an agent similar to the wind, to the
agitated air, to the breath, which produces, invisibly, effects that we
perceive. By subtilizing, the modern theologian becomes as little
intelligible to himself as to others. Ask him what he means by a spirit?
He will answer, that it is an unknown substance, which is perfectly
simple, which has nothing tangible, nothing in common with matter. In
good faith, is there any mortal who can form the least idea of such a
substance? A spirit in the language of modern theology is then but an
absence of ideas. The idea of spirituality is another idea without a
model.