Logical Opposition Flashcards
This is considered to be a kind of mental reasoning
wherein the mind passes directly from one premise to
the conclusion without using mediums.
immediate inference
◦ It is significant to be understood in logic because: 1)
it develops facility of recognizing quality and
quantity in propositions; and it helps in
understanding the relationships of propositions with
one another regarding their truth and falsity
immediate inference
The logical relation that exists between two standard-form
categorical propositions that differ in quantity, quality or
other respects.
logical oppositions
This relationship is sort of explained in the Traditional
Square of Opposition, as formulated by Aristotle.
logical oppositions
logical opposition relationship is sort of explained in the
traditional square of opposition
immediate inference is important in logic because it develops facility of recognizing quality and
quantity in propositions
true
immediate inference is important in logic because helps in
understanding the relationships of propositions with
one another regarding their truth and falsity.
true
kinds of logical opposition
contrary
subcontrary
contradiction
subalternation
Propositions that are neither
necessary true or false are said to
be
contingent
◦ They cannot be both true, but can
be both false.
◦ If a proposition is true, then the
other one should be false, but not
vice versa.
contrary
◦ They cannot be both false but
they can be both true.
◦ If one proposition is false, then
the other must be true, but not
vice versa.
subcontraries
They cannot be both true and
both false at the same time.
◦ If one is true, then the other is
false, and vice versa.
contradiction
Rule 1: if the universal is true, then
the particular is also true, but not
vice versa.
◦ Rule 2: if the particular is false, the
universal is false, but not vice versa
subalternating
Universal propositions (A,E) are
called as
superaltern
; particular
propositions (I,O) are called as
subaltern
