(4) From the truth of the particular no conclusion follows as to the universal.
From the falsity of the universal no conclusion follows as to the
particular.
(5) If the conclusion in the fourth figure be negative, the major
premiss must be universal.
If the major premiss in the fourth figure be particular, the
conclusion must be affirmative.
(6) If both premisses be affirmative, the conclusion must be
affirmative.
If the conclusion be negative, one of the premisses must be
negative.
4. 'The Method of Agreement stands on the ground that whatever circumstance can be eliminated is not connected with the phenomenon by any law; the Method of Difference stands on the ground that whatever circumstance cannot be eliminated is connected with the phenomenon by a law.' Do these two principles imply one another?
CHAPTERS XX-XXVIII.
1. Fill up the following enthymemes, and state the exact nature of the resulting syllogism—
(1) If Livy is a faultless historian, we must believe all that he tells us; but that it is impossible to do.