22. Our complex idea of an immaterial spirit and our complex idea of body compared.
Let us compare, then, our
complex idea of an immaterial spirit with our complex idea of body, and see whether there be any more obscurity
in one than in the other, and in which most. Our idea of body, as I think, is an extended solid substance, capable of
communicating motion by impulse: and our idea of soul, as an immaterial spirit, is of a substance that thinks, and
has a power of exciting motion in body, by willing, or thought. These, I think, are our complex ideas of soul and
body, as contradistinguished; and now let us examine which has most obscurity in it, and difficulty to be
apprehended. I know that people whose thoughts are immersed in matter, and have so subjected their minds to
their senses that they seldom reflect on anything beyond them, are apt to say, they cannot comprehend a thinking
thing, which perhaps is true: but I affirm, when they consider it well, they can no more comprehend an extended
thing.