A shift of meaning that arises within an argument as a consequence of changes…

Concept

In informal logic, one family of fallacies is called the fallacies of ambiguity: they occur when a single expression carries two different meanings inside one argument, so the premise and the conclusion are not really about the same thing. Each member of that family is identified by the device that produces the shift of meaning. When the device is stress — the sense of a passage changes according to which word or part is emphasised — the fallacy committed is the fallacy of accent.

Application

1. Locate the trigger the stem names: the meaning shifts “as a consequence of changes in the emphasis given to its words or parts”. That places the defect in stress — not in grammatical structure, not in the misuse of a general rule, and not in a whole-to-part transfer.

2. Take one sentence and vary nothing but the emphasis: “We should not speak ill of our friends.” Read flat, it forbids speaking ill of friends and says nothing at all about anybody else.

3. Now lean on the last word — “we should not speak ill of our friends” — and the same string of words suggests that speaking ill of people who are not our friends is permitted.

4. No word was added, removed or reordered; only the accent moved. An argument that takes the second reading as licensed by the first sentence has committed the fallacy of accent.

Contrast with the other fallacies offered

• Amphiboly: the meaning shifts because the grammatical construction admits two parsings — “The professor announced on Monday there would be a test” leaves “on Monday” attachable either to the announcement or to the test. The defect lies in sentence structure, not in stress.

• Accident: a sound general rule is applied to a case whose special circumstances put it outside the rule’s intended scope — inferring from “borrowed things must be returned” that a borrowed weapon must be handed back to an owner who is in a rage.

• Division: a property that holds of a whole or of a class is transferred to each of its parts or members — “this machine is heavy, so every one of its components is heavy”.

Among the fallacies offered, the one defined by an emphasis-driven change of meaning is the fallacy of accent.