King's Commission. Let me call your attention to the fact that my opponent admits the validity of this report. His chief objection to it is that it covers only about a quarter of the territory in question. That is true. But bear in mind that the other three quarters of the state is entirely closed to the world. The Commission covered that part of the territory which is in closest touch with civilization. Yet the rubber collection is carried on throughout the whole state. If this collection is attended by such horrors as I have shown in that part closest to civilization, what must be the condition in that section into which civilization has not entered!

We should test all arguments from analogy to .find, if possible, reasons why the facts known to be true of the analogous cases are more likely or less likely to be true of the cases in question.

A Fifth Test of the Argument from 'Analogy. - So far the aim of our tests has been to determine to what extent the alleged points of similarity or difference in parallel cases justify the inference by analogy. In other words, we have so far tested only the validity of the reasoning process. But we may object to an argument from analogy on quite another ground, namely, by questioning the facts alleged to be true either of the example or of the case under dispute.

We may take an illustration from the daily press. A Baltimore newspaper, in an attempt to prove that military drill should be compulsory for boys in the public high schools of that city, cited the experience of Boston as an example. The argument ran somewhat like this: Boston and Baltimore resemble each other closely in all the features which bear essentially on the question; therefore, since military drill has been successful in Boston high schools, it would prove successful in Baltimore high schools. The inference in this argument from

analogy appears to have no glaring defects; it stands all the tests. But the alleged facts may well be questioned. Has military drill really been a success in the schools of Boston? This test of the facts, rather than the tests of the reasoning process, would be most likely to reveal the weakness of the argument.

A man would be arguing from analogy who attempted to prove that the United States Government should own and control the railroads because of its success with the postal system. An opponent might discredit this analogy by showing that the government had not been reasonably economical and effective in its management of the postal system, as shown by the less expensive and more convenient parcels-post systems of other countries. This would be adducing an argument from analogy to disprove a premise of another argument from analogy.

Debaters sometimes seek to divert attention from the fatal flaws in their arguments by devoting much time to those possible objections which they are prepared to meet. Thus, in using an argument from analogy, they take great pains to prove the two cases analogous, while they assume, without proof, the truth of the alleged facts on which the analogy is based. Any one who is aware of the chief sources of error in each kind of argument will be on his guard against such misleading devices of tricky opponents.

We should test all arguments from analogy to determine whether the alleged facts are true.

If we can verify an argument from analogy by the application of all of these tests, so much the better. On

the other hand, if an analogy fails to satisfy several of these tests, the proof of its worthlessness may be all the more convincing. Some of the examples given above are evidently open to objection on more than one ground.

SUMMARY OF THE TESTS OF THE ARGUMENT FROM ANALOGY

1. Are the details of comparison and contrast essential to the question at issue?

2. Do the points of likeness outweigh the points of difference?

3. Is the conclusion reached by analogy verified or discredited by other kinds of proof?

4. Is the fact known to be true of the analogous case even more likely to be true of the case in question? 5. Are the alleged facts on which the analogy is based really true?

SIXTH CHAPTER

PROVING THE PROPOSITION: ARGUMENT

FROM CAUSAL RELATION

"Our belief in what we call the evidence of our senses is less strong than our faith that in the orderly sequence of events there is a meaning which our minds could fathom were they only vast enough.' FISKE.

JOHN

WE have examined the classification of all argument into inductive and deductive argument as the basis of the science of logic, and as a means whereby to test the validity of simple reasoning processes. We have seen, further, that inductive reasoning in practical affairs takes the form of the Argument from Example - either as Generalization or as Analogy — and is often the best to be had. As the ultimate justification of all such Arguments, however, we have looked to underlying causal relations. As no reasoning- not even a generalization which satisfies all other tests can commend itself except on the assumption that a causal relation exists, we may derive considerable help in our own reasoning by studying arguments which direct attention to causal connections. All such arguments proceed from effect to cause, from cause to effect, or from effect to effect. All rest on the universal belief in causation: nothing happens without sufficient cause.

As every inference is a step from what we start with to what the inference teaches, the argument from effect to cause and the argument from cause to effect are both processes of reasoning from the known to the unknown

The difference is that one process argues from a known effect to an unknown cause, whereas the other argues from a known cause to an unknown effect. If we start with an observed act of a human being and attempt to find a motive for that act, we argue from effect to cause. If we start with a known motive and attempt to prove that it will result in a certain act, we argue from cause to effect. The argument from effect to cause, therefore, is based on matters after the disputed fact, whereas the argument from cause to effect is based on matters before the disputed fact.

I. ARGUMENT FROM EFFECT TO CAUSE

The argument from effect to cause attempts to prove that a given cause operates or has operated by pointing to an observed effect which could be due to no other cause. This kind of argument is from a known effect to its supposed cause, as when we hold that the observed movements of a heavenly body can be accounted for only by the supposition that a planet yet undiscovered is operating as cause. In like manner we try to prove that an event happened by pointing out phenomena likely to have been produced by that event, in case it actually did happen. Coming suddenly upon a clearing in the woods beside an inviting spring, we find a bed of boughs and the ashes from a small fire. We conclude that somebody has camped there. We argue from what comes after to what we believe must have gone before.1 We go back to a period of time before an observed act and select from antecedent circumstances, known and inferred, those which have a probable causal connection with the observed act.

1 This is called a posteriori reasoning, the term meaning “from what comes after."