society, the belief in the laws of causation is universal. Upon this sound basis must every argument find its ultimate justification. Even inductions and deductions may be traced to their source where the law of cause and effect will finally determine their validity. It is therefore of the utmost importance that we give careful consideration to this class of arguments. As in the case of imperfect induction, we are reasoning from the known to the unknown; from things of which we are conscious to things that are beyond the realm of our perception. We shall consider the form of these arguments and the conditions with which they must comply in order to be valid.

I. Argument from effect to cause.

The argument from effect to cause is one which relies upon an observed effect to prove the operation of an unobserved cause. Upon arising in the morning I observe that the ground which was bare the evening before is now white with snow. Therefore I reason that snow must have fallen during the night, although no snow is now falling and I have not seen any snow in the actual process of falling. The snow-covered ground is the effect which I observe and the unobserved fall of snow during the night is the only possible cause for this effect. If a friend who has not yet seen the snow disputes my assertion that there was a snowfall during the night by saying that it is too warm to snow, I may effectively establish my argument and refute his own by calling him to the window and pointing to the snow. I should point to the effect as establishing the existence of the cause. This would be conclusive evidence of the truth of my statement.

The argument from effect to cause is based upon things observed after the disputed fact. This process is called a posteriori reasoning which means reasoning from that which comes after. This is the process of reasoning employed by

the detective in tracing a criminal. The detective by means of skillful observations taken after a crime is committed reasons back to the person who is guilty. The fact that the criminal has usually made an attempt to avoid leaving any traces that may be used as a basis of a posteriori reasoning makes this process a most interesting one and accounts for much of the popularity of detective stories.

This use of reasoning from effect to cause was first popularized by the detective stories of Edgar Allan Poe and appears to have reached its climax in the Adventures of Sherlock Holmes, the creation of Sir A. Conan Doyle. Sherlock Holmes possesses remarkable powers of observation. He notices that a young lady who calls to see him has finger tips that are slightly spatulate. From this effect he reasons back to the cause and determines that it is the result of much use of the piano. From this and other observations he reasons that the young lady is a musician. He observes that a farmer has a certain kind of mud on his boots and reasons that the man has just come from a particular town near London where such mud is to be found. The certain kind of mud on the farmer's boots is the effect; the recent presence of the farmer in that particular town near London is the cause. Observing the effect Holmes reasons back to the cause, or in other words, he constructs an argument from effect to

cause.

The application of this process of reasoning to the practice of argumentation and debate is easily seen. The politician who says that the high cost of living is due to the growth of monopolies employs an argument from effect (i. e., the high cost of living) to cause (i. e., the growth of monopolies). The minister who declares that the prevalence of drunkenness is due to the licensed saloon expounds an argument from effect (i. e., the prevalence of drunkenness) to cause (i. e., the licensed saloon). The student who asserts that his class dues

are excessive because the business of the class is poorly managed uses an argument from effect (i. e., excessive class dues) to cause (i. e., poor management).

In order to be sound an argument from effect to cause must conform to the following requirements:

1. The alleged cause must be sufficient to produce the effect.

When the existence of a definite cause is alleged to have produced an observed effect, the burden of proving the sufficiency of that cause rests upon him who asserts its operation. No fault of reasoning is more common than that of regarding an insufficient cause as sufficient. If a man is successful we attribute his success to one quality, such as perseverance; whereas his success may be due to a combination of qualities. There may be a hundred other men who possess more perseverance and yet fail. When a financial panic occurs we attribute it to the rule of a certain political party; whereas the action of that party may have been the smallest of the factors causing the panic. Perseverance may be a quality contributing to success, but perseverance alone is not sufficient to secure success. The action of a political party may aid in producing a panic, but seldom are conditions such that its action alone is sufficient to produce a panic. The question of what is sufficient cause demands the exercise of sound judgment. A fall of three feet would hardly be regarded as a sufficient cause for the death of a man; a fall of one hundred feet would be regarded as sufficient cause for his death. Between these two extremes the individual judgment considering other circumstances connected with such an event, must determine the adequacy of the cause to produce the result in any given case. It is therefore plain that the debater who points to a result as produced by a definite cause must show the adequacy of that

cause.

2. No other cause must have intervened between the alleged cause and the effect.

cause.

A clear field must be shown for the operation of the alleged This can be done by proving that no other cause could have produced the observed effect. Other causes which might possibly have produced the effect must be shown to have been inoperative or inadequate. For example, a student fails in his studies. He is called before the delinquent board of the faculty and explains his failure by arguing that he has had poor health. He alleges poor health as the cause of the observed effect-the failure in his studies. A member of the board, however, is skeptical regarding the validity of the argument and asks him if it is not true that each week he attends the theatre at least once and sometimes as often as four times. The student is forced to admit that such is the case. Further inquiry reveals the fact that he has been attending a dancing school one night each week; that he belongs to a club which meets every Tuesday and Friday night; and that he is known to spend much of his time in a public billiard room. These facts show an independent cause (i. e., general dissipation) which has intervened between the alleged cause (i. e. poor health) and the effect (i. e., failure in his studies). The student has therefore failed to prove his argument that poor health, which is a legitimate cause, is responsible for his failure. The evidence shows that general dissipation, which is not a legitimate cause, has intervened between the alleged cause and the effect.

If the student had been able to show that he had been diligent in his efforts, had attended to business in a reasonable manner, and that his previous record had been satisfactory he would have established his argument that ill health was the cause of his failure. In every argument from effect to cause the adequacy of the alleged cause must first be shown and then evidence must be produced establishing the fact

that no cause, other than the one alleged, produced the effect.

3. The alleged cause must not have been prevented from operating. As stated in the preceding section the alleged cause must have a clear field for action. Not only must no other cause have intervened to produce the effect attributed to the alleged cause, but no forces must have intervened to prevent the alleged cause from operating. Any circumstance which appears to have prevented the operation of the alleged cause should be examined carefully. One morning a man Iwas found dead near the railroad. As there were some bruises on his body, the cause of his death was attributed to his being struck by a local freight which passed that point at midnight. No other train passed over this road at night and the man had been killed sometime within six or eight hours of the time when he was found. The case seemed clear. The result (death) was apparently due to the alleged cause (a freight train). Investigation, however, revealed tha fact that the freight train had not run that night on account of a wreck on a branch line. Therefore an outside force, viz., the wreck, had prevented the alleged cause from operating. Hence it could not be the true cause. The inquiry into the alleged cause ultimately resulted in the revealing of the true cause-willful murder.

In arguing from effect to cause the adequacy of the alleged cause must be proved, the fact that no other cause intervened between the alleged cause and the observed effect must be clearly demonstrated, and the circumstances of the case must show that the alleged cause was not prevented from operating. With these requirements fulfilled such an argument may be regarded as sound. It will be seen that the application of these rules requires sound judgment and practical common sense. The argument will be effective in persuading