(Jeanne Fahnestock, Rhetorical Style: The Uses of Language in Persuasion. The list strengthens what was already, on the occasion of Roosevelt's speech, an overwhelming case for war." In the most direct manner, the six examples of Japanese aggression 'add up' to the conclusion. The argument form here, supporting a generalization with examples, is classically known as induction. His 'therefore' signals that he offers a conclusion supported by the preceding list, and these individual instances have been united as examples for the conclusion on the basis of their parallel form. (Safire 1997, 142 see also Stelzner 1993) Here, Roosevelt has in effect constructed a comparison that involves six items, and his purpose in doing so appears in the final sentence. Japan has, therefore, undertaken a surprise offensive extending throughout the Pacific area. Last night, the Japanese attacked Wake Island.Īnd this morning, the Japanese attacked Midway Island. Last night, Japanese forces attacked the Philippine Islands. Last night, Japanese forces attacked Guam. Last night, Japanese forces attacked Hong Kong. Yesterday the Japanese government also launched an attack against Malaya. Roosevelt's speech to Congress on December 8, 1941, the day after Pearl Harbor, declaring a state of war between the United States and Japan. "The following passage comes from Franklin D.Cavender, Logic and Contemporary Rhetoric, 1998) (Conclusion) "We use inductive reasoning so frequently in everyday life that its nature generally goes unnoticed."
(Premise) I suppose it's time to face facts: He's never going to pay me back. (Premise) I loaned him another $50 just before Christmas, which he hasn't paid back (Premise), and yet another $25 in January, which is still unpaid. "Here is a simple example of an inductively valid argument of the kind sometimes called induction by enumeration: I loaned my friend $50 last November and he failed to pay me back. We often observe patterns, resemblances, and other kinds of regularities in our experiences, some quite simple (sugar sweetening coffee), some very complicated (objects moving according to Newton's laws-well, Newton noticed this, anyway). The idea behind valid induction is that of learning from experience.
(Martin Gardner, Skeptical Inquirer, Jan.-Feb., 2002 But if a crow is found to be not black the conjecture is falsified." Each time a new crow is observed and found to be black the conjecture is increasingly confirmed. A common example is the hypothesis that all crows are black. It either advances a conjecture by what are called confirming instances, or it falsifies a conjecture by contrary or disconfirming evidence.