Fallacies of reasoning

Logical Fallacies: Arguments, Reasoning, and the Fallacy
Fallacies are defects in an argument that cause it to be invalid, unsound, or weak. In a deductive argument, the existence of a fallacy means that the argument is not valid - even if the premises are true, the conclusion might still be false. A fallacy does not guarantee it is false; a fallacious argument fails to provide a good reason to believe the conclusion, even if that conclusion is correct.