the foregoing three chapters, to supply the body with wholesome
substances and to exclude unwholesome substances, but it is also
necessary that the body should at times act, and at other times be
inactive
In order to live a hygienic life it is not only necessary, as shown in
the foregoing three chapters, to supply the body with wholesome
substances and to exclude unwholesome substances, but it is also
necessary that the body should at times act, and at other times be
inactive. There are two great forms of activity, work and play; and two
great forms of inactivity, rest and sleep. All four of these are needed
in the healthy life and in due relation to each other.