INFORMAL FALLACY DEFINITIONS
GROUP 3, TEST #3

Describe the a priori - fallacy.

The a priori - fallacy occurs when someone decides ahead of time what the conclusion to an argument is, then only considers evidence that supports that conclusion, or twists what evidence there is to support the predetermined conclusion.

For example, in the early 1950's during the Communist "witch hunts" some people determined ahead of time that communists were in sensitive positions in the government. If a government agency did something the anti-communists disapproved of, they took it as proof of the communist infiltration. If a government employee disagreed with the anti-communists, that was evidence the employee was a communist. Accused persons were often given little chance to defend themselves because, after all, they would just lie. If an accused person denied being a communist that was proof he was a communist because, of course, a communist agent would deny being one. The investigator's minds were made up ahead of time and they would not be swayed by evidence.

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