system in general: either with or without the guidance of
the will. The shivering produced by cold, implies irregular muscular
contractions, which, though at first only partly involuntary, become,
when the cold is extreme, almost wholly involuntary. When you have
severely burnt your finger, it is very difficult to preserve a dignified
composure: contortion of face, or movement of limb, is pretty sure to
follow. If a man receives good news with neither change of feature nor
bodily motion, it is inferred that he is not much pleased, or that he
has extraordinary self-control--either inference implying that joy
almost universally produces contraction of the muscles; and so, alters
the expression, or attitude, or both. And when we hear of the feats of
strength which men have performed when their lives were at stake--when
we read how, in the energy of despair, even paralytic patients have
regained for a time the use of their limbs, we see still more clearly
the relations between nervous and muscular excitements. It becomes
manifest both that emotions and sensations tend to generate bodily
movements and that the movements are vehement in proportion as the
emotions or sensations are intense.[2]

This, however, is not the sole direction in which nervous excitement
expends itself. Viscera as well as muscles may receive the discharge.
That the heart and blood-vessels (which, indeed, being all contractile,
may in a restricted sense be classed with the muscular system) are
quickly affected by pleasures and pains, we have daily proved to us.
Every sensation of any acuteness accelerates the pulse; and how
sensitive the heart is to emotions, is testified by the familiar
expressions which use heart and feeling as convertible terms. Similarly
with the digestive organs. Without detailing the various ways in which
these may be influenced by our mental states, it suffices to mention the
marked benefits derived by dyspeptics, as well as other invalids, from
cheerful society, welcome news, change of scene, to show how pleasurable
feeling stimulates the viscera in general into greater activity.

There is still another direction in which any excited portion of the
nervous system may discharge itself; and a direction in which it usually
does discharge itself when the excitement is not strong. It may pass on
the stimulus to some other portion of the nervous system. This is what
occurs in quiet thinking and feeling. The successive states which
co