f a school of thought, or because of the
tendency of human nature to accept plausible suggestions, is also made
apparent. Through the deliberate practice of testing and weighing, the
faculty of arriving swiftly at accurate decisions is strengthened and
is brought more quickly into play when time is a matter of immediate
concern.

Principles in their Relation to Logical Thought. Because of the
necessity for the exercise of judgment (page 3) in the systematic
arrangement of thought, the relationship between cause and effect, as
expressed in principles, is of great assistance in applying logical
processes to the problems of human life.

A principle establishes a correct relation between cause and effect.
The word, derived from the Latin "principium", meaning a foundation,
beginning, source, origin, or cause, has, because a cause implies an
effect, acquired in correct usage the significance of a true statement
of relationship between cause and effect. A principle, so formulated,
is a natural law (page 19) because it expresses a fact of nature; it
thus becomes a reliable rule of action and may be confidently adopted
as a governing law of conduct. If basic in its field, such a rule or
law becomes a general or fundamental principle with respect thereto;
each such basic truth may be the basis for the determination of many
corollary or subordinate principles dealing with the details of the
particular subject.

The formulation of a principle, therefore, requires the determination
of the causes that generate a particular effect (or effects), and the
accurate expression of the resultant relationship. Such expression
frequently takes the form of a proportion. In the mathematical
sciences the proportion may represent a precise balance; its statement
may be an exact formula. In other sciences, a definite relationship
between cause and effect has likewise been established in many cases,
though not always with mathematical precision. Comparable exactitude
has not been attained, in some cases, because the field has not been
so thoroughly explored; moreover, greater difficulty is experienced,
at times, in isolating the cause, or causes. The balance represented
by such equations, therefore, is based on quantities whose weights
vary within wide ranges. (See page 3.)

Human conduct does not lend itself to analysis as readily as do
mathematical and physical phenomena. The advance in the psychological
and sociological sciences is not so m