Informal Fallacies

fallacies that can be detected only by examining the content of the argument containing mistakes in reasoning or the creation of an illusion that makes a bad argument appear good

• Relevance
• Weak Induction
• Presumption
• Ambiguity
• Grammatical analogy

• share the common characteristic that the arguments in which occur have premises that are logically irrelevant to the conclusion
• the connection is emotional (emotional appeal)

• the connection btw premises and conclusion are not strong enough to support the conclusion
• the premises provide at least a shred of evidence in support of the conclusion, but the evidence is not nearly good enough to cause a reasonable person to believe the conclusion

the premises presume what they purport to prove

arise from the occurrence of some form of ambiguity either in the premises or the conclusion (or both)