A valid argument is logically valid and built with reasonable, clear premises that are supported by evidence. An argument is "good" when it is valid (or strong, if it is inductive) and its premises are acceptable and relevant. It is fair to accept a premise when it comes from a reliable source or can be independently verified.

Personally, I remember having to defend a paper on Euthanasia. The professor said, "It is good to end the suffering of people when they are convalescing." I used a strategy based on explaining the difference between dying naturally and killing, supporting my point with data from scientific organizations like the Scientific Journal 2.0. This kind of reasoning falls under logical refutation and the use of empirical evidence.

Exploring categorical and propositional logic helps us adjust the way we evaluate arguments. For example, categorical syllogisms show us how certain structures can be valid or invalid. On the other hand, in propositional logic, conjunctions, disjunctions, and conditionals allow us to analyze the logical form of a reasoning.