Certain and Probable Knowledge

From Summa Bergania

Examples of certain knowledge would be anything demonstrated by a mathematical, geometric, or logical proof. (“11 x 11 = 121,” “Parallel lines cut by a transversal produce congruent interior angles,” or “Since all cats are mammals and all lions are cats, therefore all lions are mammals.”)

Examples of probable knowledge include daily events, scientific knowledge, history, and personal observations. (“The temperature rose above 50 degrees today,” “Protons are made up of quarks,” “George Washington was the first President of the United States,” “My car is showing rust spots.”)