Suitability of the end in view, as determined by the factor
of the appropriate effect desired,

Feasibility of the effort required, on the basis of
comparative resources, as determined by the means
available and opposed, influenced by the factor of the
physical conditions prevailing in the field of action, and

Acceptability of the results of the effort involved, as
determined by the factor of the consequences as to costs,

which factors are in turn dependent on each other.

The Interdependency of the Factors. As previously observed (page 28),
the factors cited in the foregoing principle are themselves
interdependent. This fact results from working of natural law (page
22), for it is a recognized phenomenon that every effect is the result
of certain causes, and that every effect is itself, in turn, the cause
of further effects (page 19).

Accordingly, when the evaluation of any factor is under consideration,
its value as an unknown quantity can be determined to the extent that
the values of the other pertinent factors are known. (See page 23, as
to the discussion of the quantities in an equation.) The significance
of each, in any situation, is therefore determined by the influence of
the other factors. The relationships existing among them can best be
expressed in the terms of four corollary principles (page 27), next to
be discussed.

* * * * *

For example, questions frequently arise as to what is the appropriate
effect to be desired in a particular situation. Whether a desired
effect is feasible of attainment, and whether certain consequences,
though undesirable, will be acceptable, in view of the gains, can be
determined by evaluation of the means available and opposed,
influenced by the physical conditions prevailing in the field of
action, and of the consequences as to costs. If a desired effect is
thereby found to be not feasible of attainment, or to be unacceptable
as to consequences, deferment of such effort is indicated. A proper
solution in such case would adopt some lesser effect, in conformity
with the further aim, feasible of accomplishment, and acceptable as to
its consequences.

If (with respect to the further aim, mentioned above) the person
concerned is acting under the instructions of another, there will
frequently be injected into the equation, in addition to the factors
already noted, a further effect