4. The principles adduced as evidence
(a) Are they axiomatic?
(b) Are they truths of general experience?
(c) Are they truths of special experience?
(d) Are they truths arrived at by experiment? Were such experiments special or general? Were the experiments authoritative and conclusive?
III. THE REASONING
1. Inductions
(a) Are the facts numerous enough to warrant accepting the generalization as being conclusive?
(b) Do the facts agree only when considered in the light of this explanation as a conclusion?
(c) Have you overlooked any contradictory facts?
(d) Are the contradictory facts sufficiently explained when this inference is accepted as true?
(e) Are all contrary positions shown to be relatively untenable?
(f) Have you accepted mere opinions as facts?
2. Deductions
(a) Is the law or general principle a well-established one?
(b) Does the law or principle clearly include the fact you wish to deduce from it, or have you strained the inference?
(c) Does the importance of the law or principle warrant so important an inference?
(d) Can the deduction be shown to prove too much?
3. Parallel cases
(a) Are the cases parallel at enough points to warrant an inference of similar cause or effect?
(b) Are the cases parallel at the vital point at issue?
(c) Has the parallelism been strained?
(d) Are there no other parallels that would point to a stronger contrary conclusion?
4. Inferences
(a) Are the antecedent conditions such as would make the allegation probable? (Character and opportunities of the accused, for example.)
(b) Are the signs that point to the inference either clear or numerous enough to warrant its acceptance as fact?
(c) Are the signs cumulative, and agreeable one with the other?
(d) Could the signs be made to point to a contrary conclusion?
5. Syllogisms
(a) Have any steps been omitted in the syllogisms? (Such as in a syllogism in enthymeme.) If so, test any such by filling out the syllogisms.
(b) Have you been guilty of stating a conclusion that really does not follow? (A non sequitur.)
(c) Can your syllogism be reduced to an absurdity? (Reductio ad absurdum.)
QUESTIONS AND EXERCISES
1. Show why an unsupported assertion is not an argument.
2. Illustrate how an irrelevant fact may be made to seem to support an argument.
3. What inferences may justly be made from the following?
