DIFFERENT KINDS OF DEMONSTRATION.

64. I. Primary Division. -- A demonstration is a reasoning which proceeds logically from certain premises to a certain conclusion. And in a more perfect sense, it is a syllogism which furthermore produces true knowledge, i. e., makes us "know the cause of the thing, know that that cause is really the cause of the thing, and that, consequently, the thing could not be otherwise than we know it."^{1}

There is a primary distinction between the demonstration which produces a certain conclusion and that which produces a strictly scientific conclusion.

{1} Aristotle, Posterior Anal., 1, 2.