Translating ordinary language into categorical form
In translating ordinary language into categorical form, one must consider
what is being talked about (the logical subject) and what is being asserted
about it (the logical predicate). For example: "Banks that make too many
risky loans will fail." In this English sentence, the noun
banks is the what is being talked about thus the logical
subject. The author limits the class being talked about by adding the
clause that make too many risky loans. The author is
asserting that banks that make to many risky loans are banks that
fall into the class (logical predicate) of institutions that
will not succeed. She expresses this logical assertion by using the
English verb will fail.
To put all of this information into a categorical proposition:
1.
Identify the logical subject and logical predicate. In this
example, banks that make too many risky loans is the logical
subject , and, since the logical subject and the logical predicate must
be a noun, institutions that will fail is the logical
predicate. NOTE: The predicate must be a broader class than the
subject in an affirmative proposition.
2.
Determine the quantifier based on the logical schema of the four categorical
propositions. In this example, ask yourself if the author is concerned
about all banks that make risky loans or only some banks that
make to many risky loans.
3. Determine the quality of the statement
either affirmative or negative. In the example, the author makes a
positive assertion concerning the inclusion of the subject class in the predicate
class.
The result of applying these three
guidelines is:
All (banks that make too many risky loans)
are (institutions that will fail).