166 NATURE OF CAPITAL AND INCOME [Crar. X
objective services are of significance to man except as they
are preparatory to subjective satisfactions.
The final subjective services come through the human
body. No agent outside the body can yield them. All
that persons or things outside of man can do is to stimulate
his bodily organism. Even what are called services of amuse-
ment or instruction cannot directly amuse or instruct the
mind; they can only affect the body. An instructive
book, for instance, renders its service simply and solely by
reflecting light into the eye of the reader. It is necessary
that these stimuli on the optic nerve should be transmitted
through the nervous system before any mental instruction
takes place. So a piano can of itself produce no sensations
of tone. It merely produces external vibrations, which,
through the ear and auditory nerve, ultimately result in
sensation. All sound, sight, taste, smell, touch, come
about through reactions of the nervous system to external
stimuli. A man who receives a Turkish bath has received
enjoyable income in the objective sense, but all the serv-
ices of the water, towels, attendants, and other codperat-
ing agencies, while credited to them, must, if we treat man
himself as capital, be regarded as debited to him. They
result simply in cleaning and stimulating his skin. They
are income from outside agencies absorbed by his body in
order that he may later experience pleasant sensations or
avoid unpleasant ones, through the enjoyment of health.
Similarly the use of clothing and shelter prevents the
occurrence of the sensation of cold, but their immediate
objective service is simply in hindering the dissipation of
heat from the body. They are disservices with reference to
the body, just as similar care and protection of a horse are
disservices with reference to it.
When medicine is taken, it may, from the objective stand-
point, be counted as a part of income, just as food, clothing,
and other ordinary items. But it is clear that the services
of medicine are (or are supposed to be) the repairing of the
