II. SYLLOGISMS CONSIDERED WITH REFERENCE TO THEIR MATTER.

63. Preliminary Remarks. -- Syllogisms are divided, in respect to their matter, according to the relations of their propositions with the truth. Now, judgments are certain, probable, or erroneous; and syllogisms, accordingly, are demonstrative, probable, erroneous.

(1) The judgment is certain when the mind firmly adheres to what it knows to be the truth: a syllogism which leads to certitude is a demonstration.

(2) So long as the mind remains between two opposite judgments without definitely adhering to either of the two, it is in suspense, -- it doubts. When it inclines to one side or the other, but without adopting either side absolutely to the exclusion of the other, it has an opinion: the syllogism is probable when it begets an opinion, and its probability is in the direct ratio of the strength of the motives which induce the partial adherence of the mind.

(3) The contrary of truth, the disagreement of the judgments with the thing known, is error: syllogisms which lead to error are called sophistical.

We proceed to examine in order demonstrations, probable arguments, and those sophisms which are chiefly worthy of our attention.