fever is in turn infallibly linked with a mental experience called
restlessness and delirium. To abolish the mental experience the
radical method would be to abolish the physical experience, and
the way of abolishing the physical experience would be to abolish
Africa, or to cease to go there.

Now this hold good for all other forms of Restlessness. Every other
form and kind of Restlessness in the world had a definite cause,
and the particular kind of Restlessness can only be removed by
removing the allotted cause.

All this is also true of Rest. Restlessness has a cause: must
not REST have a cause? Necessarily. If it were a chance world we
would not expect this; but, being a methodical world, it cannot be
otherwise. Rest, physical rest, moral rest, spiritual rest, every
kind of rest has a cause, as certainly as restlessness. Now causes
are discriminating. There is one kind of cause for every particular
effect and no other, and if one particular effect is desired, the
corresponding cause must be set in motion. It is no use proposing
finely devised schemes, or going through general pious exercises
in the hope that somehow Rest will come. The Christian life is
not casual, but causal. All nature is a standing protest against
the absurdity of expecting to secure spiritual effects, or any
effects, without the employment of appropriate causes. The Great
Teacher dealt what ought to have been the final blow to this infinite
irrelevancy by a single question, "Do men gather grapes of thorns
or figs of thistles?"

Why, then, did the Great Teacher not educate His followers fully?
Why did He not tell us, for example, how such a thing as Rest might