Logic is the study of correct reasoning. Formal logic aims to determine the correctness of arguments based on their structure alone and often uses a formal language to analyze them. Informal logic examines arguments expressed in natural language and also takes their content and context into account. Logic distinguishes between deductive, inductive, and abductive arguments. Deductive arguments have the strongest form of support: if their premises are true then their conclusion must also be true, such as in the argument "today is Sunday; if today is Sunday then I do not have to work today; therefore I do not have to work today". Inductive arguments are generalizations, like inferring that all ravens are black based on many individual observations. Abductive arguments are inferences to the best explanation, for instance, when a doctor concludes that a patient has a certain disease that explains the symptoms they suffer. Arguments that fall short of the standards of reasoning embody fallacies. (Full article...)