dinate would ordinarily reach for himself.

Such procedure may be deemed advisable under certain circumstances:
for example, when time is pressing; when a close control of the
situation is an important factor; when the qualifications of the
subordinate are unknown, as yet doubtful, or known to be inadequate
for the operation in hand; or, for various other reasons which may
suggest themselves according to the nature of the problem.

Occasionally, higher authority, for similar reasons, may also
prescribe the action to be taken, in considerable detail. Examples
occur during operations of unusual complexity, or when the personnel
factors call for special care in coordination of the action.

Sometimes, higher authority, instead of announcing both the task and
the predetermined course of action, may indicate only the latter; in
the example given above, the higher commander would then direct,
"Capture X Island". The directive might also include, in some detail,
the action to be taken to this end.

Procedure such as noted in the foregoing examples involves certain
special considerations from the viewpoint of the subordinate. These
considerations are discussed hereafter (page 96).

The Mission. In our naval service an assigned task, coupled with its
purpose, is known as a mission. As explained previously (page 48), the
purpose indicates the larger aim which is to be served by the
execution of the task. The task indicates the assigned objective,
i.e., what is to be accomplished; the purpose, the further objective
to be served thereby.

The word mission is a derivative of the Latin verb, "to send". Its use
implies the act of sending someone, or of being sent, as an agent for
some special duty, a duty imposed by one in authority. Although an
individual, free to do so, may select his own mission, and thereby
send himself on a special duty, this is not usually the case where an
effective military chain of command exists. Normally the sending
authority is the immediate superior; the agent, the immediate
subordinate.

The mission, once assigned, does not change until it has been
accomplished or until it has been modified or revoked by higher
authority, usually the immediate superior by whom it was assigned.

As previously explained in this connection, the designation of a
purpose, linked with a task, is an essential element of a mission as
treated herein. It is essential to unity of effort that the purpose of
the mission of a