An introductory text-book of logic - Mellone, Sydney - Rare Books at ...

212 CONDITIONAL ARGUMENTS AND
The student should notice that a hypothetical syl
logism with a disjunctive antecedent or consequent
must not be mistaken for a dilemma. Dr Fowler gives
the following examples :
(1) Whether geometry be regarded as a mental discipline
or as a practical science, it deserves to be studied ;
But geometry may be regarded as both a mental
discipline and a practical science ;
. .It deserves to be studied.
(2) If we go to war, we must either contract a debt, or
increase the taxation, or indemnify ourselves at the
enemy s expense ;
We shall not be able to do any of these ;
. .We
are not able to go to war.
EXERCISE XV.
1. What are the rules of hypothetical syllogisms? To
what rules of categorical syllogism do they correspond?
[O.]
2. Explain and justify your opinion as to whether hypo
thetical syllogisms are, or are not, to be regarded as in
stances of mediate reasoning. [L.]
3. Explain what is meant by a dilemma in Logic. Does
the following correspond to your definition? "If he man
aged to escape he must have been either very clever or very
rich but he was both ; stupid and poor, so he cannot have
escaped." [C.]
4. Examine each of the following arguments, reducing
it to logical form, if possible :
some would
(1) (a) If all men were capable of perfection,
but none having done so, none
have attained it ;
are capable of it.
(b) If any objection that can be urged would justify
a change of established laws, no laws could
reasonably be maintained ; but some laws can
reasonably be maintained ; therefore no objec
tion that can be urged will justify a change of
established laws.
(2) (a) If a man is educated, he does not want to work