section_path: Core branches/Logic
section_name: Logic
paragraph_text: Logic
  
  Logic is the study of correct reasoning. It aims to understand how to distinguish good from bad arguments. It is usually divided into formal and informal logic. Formal logic uses artificial languages with a precise symbolic representation to investigate arguments. In its search for exact criteria, it examines the structure of arguments to determine whether they are correct or incorrect. Informal logic uses non-formal criteria and standards to assess the correctness of arguments. It relies on additional factors such as content and context.
  
  Logic examines a variety of arguments. Deductive arguments are mainly studied by formal logic. An argument is deductively valid if the truth of its premises ensures the truth of its conclusion. Deductively valid arguments follow a rule of inference, like modus ponens, which has the following logical form: " p; if p then q; therefore q ". An example is the argument "today is Sunday; if today is Sunday then I don't have to go to work today; therefore I don't have to go to work today".
  
  The premises of non-deductive arguments also support their conclusion, although this support does not guarantee that the conclusion is true. One form is inductive reasoning. It starts from a set of individual cases and uses generalization to arrive at a universal law governing all cases. An example is the inference that "all ravens are black" based on observations of many individual black ravens. Another form is abductive reasoning. It starts from an observation and concludes that the best explanation of this observation must be true. This happens, for example, when a doctor diagnoses a disease based on the observed symptoms.
  
  Logic also investigates incorrect forms of reasoning. They are called fallacies and are divided into formal and informal fallacies based on whether the source of the error lies only in the form of the argument or also in its content and context.