You are missing a third category: argument. That is to say a series of deductions starting from facts and sometimes values. The values might be opinions, but often attempts are made to use widely held opinions such that agreement can be assumed. Also facts are much harder to come by than one might think. We have data from observation and experiment and derive models and conclusions … and many call those results facts. But they are only probabilistic facts - one can assign a likelihood to their truth but full certainty is rare. Thus we must rely on rational dissection of argument to identify the most likely facts of rather than starting from some pool of known truths.