Ch 9 Obversion, Conversion, and Contraposition
which statement can be partially contraposed but isnt discused in this book?
E
which statements can be converted?
E and I
The Rule of Double Negation
a term which is not negated is equivalent to a term that is negated twice
what statements can be obverted?
all- A,I,E,O
what happens when you obvert I statements
double negative in the predicate
conversion
interchange the subject and ther predicate
what are the 3 ways to convert a statement to their logically equivalent?
obversion, conversion, contraposition
how do you partially convert the A statement All dogs are animals
some animals are dogs
obversion
1.change the quality of the sentence 2.negate the predicate
Contraposition
1.obvert the statement 2.convert the statement 3.obvert the statement
what are the 4 ways of phrasing the predicate when obverting I statements
1.place two nots at the beginning of the predicate term 2.make the second not a non- 3.place im, un, in or ir at the beginning of the predicate term 4.apply the rule of double negation
which statement can be partially converted?
A
what statements and be contraposed?
A and O