Man is a walking tool-box, manufactory, workshop and bazaar worked from
behind the scenes by someone or something that we never see. We are so
used to never seeing more than the tools, and these work so smoothly,
that we call them the workman himself, making much the same mistake as
though we should call the saw the carpenter. The only workman of whom we
know anything at all is the one that runs ourselves and even this is not
perceivable by any of our gross palpable senses.
The senses seem to be the link between mind and matter—never forgetting
that we can never have either mind or matter pure and without alloy of
the other.