>From The Hutchinson Encyclopedia:
fallacy
In philosophy, a type of mistake in reasoning or inference
(deduction or conclusion drawn from what has been implied). In
Aristotelian logic (syllogism) and in modern formal logic, there
are rules for detecting and preventing fallacies, and ensuring
that an inference is valid.
Fallacies in everyday reasoning can be less easy to detect.
Begging the question is a fallacy that occurs when one of the
premises of an argument could not be known to be true unless the
conclusion were first assumed to be true. Other fallacies include
fallacies of ambiguity; of arguing against a person, rather than
against what the person says; and of arguing that something is
true simply because there is no evidence against it.
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