(1) A premise always answers the question “Why”, and is often introduced by such words as “for,” “because,” “since,” and the like.
(2) The conclusion is usually introduced by “therefore,” “hence,” “it follows,” etc.
(3) When there are no word-signs those mentioned in the foregoing may be inserted with a view of determining which is the conclusion, and which are the premises.
Suggestions relative to completing abbreviated arguments:
(1) If the conclusion is to be supplied, select the term used twice in the premises; this, the middle term, must not appear in the conclusion. The other two terms may now be connected (copulated) to form the conclusion, the narrower term (minor) being used as the subject, unless it occurs in what clearly seems to be the major premise. (2) If either premise is to be supplied, unite the middle term with the subject of the conclusion for the minor premise, and with the predicate of the conclusion for the major premise. (3) In supplying any missing proposition, care should be taken to make the argument valid, if this can be done in conformity with good English, good sense, and the rules of logic.
As regards the determination of the figure it is well to locate the middle term first, placing above it the symbol M. Then “G” (greater) may be placed above the major term and “S” (smaller) above the minor.
3. ILLUSTRATIVE EXERCISES IN TESTING ARGUMENTS WHICH ARE ALREADY COMPLETE, REGULAR, AND LOGICALLY ARRANGED.
(1) A All M
dogs are G
quadrupeds,
A All S
greyhounds are M
dogs,
A ∴ All S
greyhounds are G
quadrupeds.