Logical Equivalnece Flashcards
An inference in which the meaning of the original
proposition is made clear in the second by the use
and removal of negatives, and by interchanging the
position of the subject and predicate.
eduction
This is a kind of logical
equivalence that proceeds
by interchanging the
subject and the predicate
terms of a proposition.
conversion
in conversion, The original proposition is
called as the ___,
while the inferred
proposition is called as the
____.
convertend
converse
rules of conversion
- Interchange the subject and
predicate terms. - Retain the quality of the
proposition. - Do not extend any term.
it means the
particular quantity is raised as a
universal quantity.
extension
types of conversion
simple
partial
both the quantity and
quality of the convertend are
retained. (conversion)
simple
only the quality is
retained. (conversion)
partial
O propositions cannot be converted.
true
This is a process of eduction
wherein the new proposition
is formulated by changing
affirmative propositions into
negative propositions.
obversion
in obversion, The original proposition is
called as the ______, while
the inferred proposition is
called as the _______.
obvertend
obverse
rules of obversion
- Retain the subject and the quantity.
- Change the quality of the
proposition. - Compliment the predicate term.
The use of the term “non” denotes that the term (subject/predicate) is a
complimentary class of the provided term
true
If a given term has already a prefix ‘non’ to it (i.e. non-cute) and you are instructed
to compliment it, do not put double ‘non’ to it anymore (non-noncute) and just
revert it to the original term (cute)
true
Using the prefix “non” in the case of “non-honest” denotes the ‘group of people
that are not honest’, hence in other terms they can be ‘liars’, ‘deceivers’, etc.;
Instead of using a contrary term, we opt to use the prefix ‘non’ instead
true
This is a process of eduction
wherein the new proposition
is formulated by transposing
the subject of the original
proposition into a predicate in
the new proposition.
contraposition
This is the combination of
conversion and obversion.
contraposition
in contraposition, The original proposition is
called as the _____,
while the inferred proposition
is called as the _______
contraponend
contraposit
two types of contraposition
simple
complete
simple contraposition rules
RULES:
1. Obvert the given.
2. Convert the obverse.
I Propositions cannot be contraposed
true
E propositions, when obversed, can only be
partially converted to get contrapositives.
true
complete contraposition rules
RULES:
1. Obvert the given.
2. Convert the obverse.
3. Obvert the converse
This is the form of logical
equivalence which involves
changing the quality of the
subject and contradicting
either the subject alone or
both of them.
inversion
in inversion, The original proposition is
called as the _____, while
the inferred proposition is
called as the _____.
invertend
inverse
two types of inversion
simpke
complete
rules of simple inversion
RULES:
1. Compliment the subject.
2. Change the quantity.
3. Change the quality.
4. Retain the original predicate.
rules of complete inversion
RULES:
1. Compliment the subject.
2. Change the quantity.
3. Retain the quality.
4. Compliment the predicate
I and O propositions cannot be
inverted
true
