Traditional logic is only concerned with [[certainty]] - one progresses from certain [[Premise_%28argument%29|premises]] to certain conclusions. There are several motivations for extending logic to deal with uncertain propositions and weaker modes of reasoning. | Traditional logic is only concerned with [[certainty]] - one progresses from certain [[Premise_%28argument%29|premises]] to certain conclusions. There are several motivations for extending logic to deal with uncertain propositions and weaker modes of reasoning. |