tantial evidence points to the boy as the culprit. Yet what
might the facts be?

In presenting arguments get as much direct evidence as possible to
prove your statements. When direct evidence cannot be secured, link
your indirect evidence so closely that it presents not a single weak
link. Let the conclusion you draw from it be the only possible one.
Make certain no one else can interpret it in any other way.

When you present evidence be sure it completely covers your
contention. Be sure it is clear. Be sure it fits in with all the other
facts and details presented. Do not let it conflict with usual human
experience. Consider the sources of your evidence. If you do not, you
can be certain your audience will. Are your sources reliable? Is the
information authoritative? Is it first-hand material, or merely
hearsay? Is it unprejudiced? Many of the other facts for evidence have
already been suggested in the chapter on getting material.

Two General Methods of Reasoning. Frequently the evidence to be used
in argumentation must be interpreted before it can be of any value,
especially when dealing with propositions of expediency or policy.
There are two general methods of reasoning. One is the inductive
method, the other the deductive.

Inductive Reasoning. When we discover that a certain operation
repeated many times always produces the same result we feel justified
in concluding that we can announce it as a universal law. After
thousands of falling bodies have been measured and always give the
same figures, scientists feel that they may state the law that all
falling bodies acquire an acceleration of 32.2 feet per second. This
illustrates the inductive method of reasoning. In this system we
reason from the specific instance to the general law, from the
particular experiment to the universal theory, from the concrete
instance to the wide principle.

All modern science is based upon this method--the experimental one.
All general theories of any kind today must--to be accepted--be
supported by long and careful consideration of all possible and
probable circumstances. The theory of evolution as applied to the
living things upon the earth is the result of countless observations
and experiments.

Hasty Generalization. The speaker cannot himself examine all the
specific instances, he cannot consider all the illustrations which
might support his position, but he must be careful of a too hasty
generalization. Having talked w