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that a censorship of moving-pictures would be futile, we might instance the failure of stagecensorship as analogous. A classic and very striking use of analogy was Patrick Henry's observation, "Cæsar had his Brutus, Charles I his Cromwell, and George III-may profit by their example." In cases like the examples cited, the analogy has a considerable convincing effect because the things compared resemble one another so closely in their essential nature. But as the essential resemblances between the analogues decrease, the convincing effect of the remaining similarity decreases. An analogy between the evolution of a machine and the evolution of a butterfly has only a decorative, or at best illustrative value.
IV. Effect to Cause
A proposition may be developed in demonstrating the truth of a statement or the existence of a phenomenon or state of affairs by arguing from effect to cause. In using this method of elaboration we prove the existence of one thing by calling attention to the indisputable presence of something which is an invariable indication of the former. For example, a flock of buzzards hovering over a southern swamp is a sign of a carcass below. The fact that people of all classes throughout the country purchase more Ford cars than any other make is a sign that these cars represent an excep
tional value for the price paid. When Patrick Henry spoke the following words, he was using a very potent argument from effect to cause:
"Ask yourselves how this gracious reception of our petition comports with those warlike preparations which cover our waters and darken our land. Are fleets and armies necessary to a work of love and reconciliation? Have we shown ourselves so unwilling to be reconciled that force must be called in to win back our love? Let us not deceive ourselves, sir. These are implements of war and subjugation, the last arguments to which kings resort. I ask, gentlemen, what means this martial array, if its purpose be not to force us to submission? Can gentlemen assign any other possible motive for it? Has Great Britain any enemy in this quarter of the world to call for all this accumulation of navies and armies? No, sir, she has none. They are meant for us; they can be meant for no other. They are sent over to bind and rivet upon us those chains which the British Ministry have been so long forging."
Attention is directed to the way in which Patrick Henry takes care to eliminate those factors which might appear to be causes for the effect under consideration. The speaker should, likewise, be sure to satisfy his audience that the effect he considers is produced by no other cause than the one which he assigns.
V. Cause to Effect
Development from cause to effect simply reverses the foregoing method of procedure. If a certain cause has in the past produced a given. effect, the speaker can from such an admittedly existing cause predict its customary effect. Or he may develop his point by showing a causal relationship between two existing phenomena; this development may, of course, proceed from cause to effect or vice versa. For example, in an address attacking modern prison reforms, the speaker might wish to elaborate the point, "Danger to Society." For this purpose he could present the lenient, trustful attitude of the reform officials toward prisoners; then point to the increasing number of escapes from prisons of the reformed type; and finally link the two phenomena by showing a cause to effect relationship.
At this point it will not be amiss to emphasize the danger of a common fallacy incident to this method of reasoning. The readiness and conclusiveness with which the average person attributes causes and effects is remarkable. "The high cost of living is due to the tariff," says Smith; "to the railroads," says Brown; "to the middleman," says Jones. Similarly, "The cause of the great war was England's envy," says one; "No, it was German militarism," says another; at which the
third and most muscular of the trio settles the matter by declaring the cause of the war to be Russian greed. Now the speaker must remember that the Browns and Smiths and Joneses with their own opinions are always present in the average audience. He will do well, therefore, to demonstrate cause and effect with care, clearing away fallacious relationships, and sometimes being content to establish a cause as contributory, or an effect as partial.
VI. From General to Specific
A useful method of elaboration is the logical sequence known as deduction. In deduction we establish the status of a specific case by classifying it under a general law or principle. The reader is probably familiar with the syllogism, as the formal process of deductive reasoning is called.
Major premise: All public nuisances should be abolished by law.
Minor premise: The uncovered ash-cart is a public nuisance.
Conclusion: Therefore, the uncovered ash-cart should be abolished by law.
In writing or speaking we rarely express the entire process; but when we say, "The uncovered ash-cart should be abolished by law because it is a public nuisance," we really use the deductive process, omitting the obvious major premise,
which the listener instinctively supplies. The minor premise is also often omitted, as when we say, "Fenton should have a public park, for every city should have a public park." Even the conclusion is sometimes merely implied; for example, "Every criminal should be brought to trial, and certainly X is a criminal."
Thus, with the omission of one of the premises or even the conclusion, we constantly use this logical sequence in developing our ideas. The chief reason for its frequent use is the fact that well-established generalizations-and only such should constitute the bases of deductions-are the results of long experience, often a part of the accumulated wisdom of generations or ages. It is, of course, absolutely essential that an audience accept the general statement, the major premise. With that assured, however, the speaker has only to show that the specific phenomenon falls under the generalization, in order to establish an inevitable conclusion. Compared with the difficulty of establishing the generalization itself, this task is simple. A very clear case in point is found in the work of a criminal lawyer, who, if he can prove his client insane, frees him from responsibility for the crime which he has committed. This is often a difficult proposition, but imagine the time it must have taken to establish the major premise, "No insane person should be held accountable