Necessary
conditions are like
minimun requirements.
A
is a necessary condition of B if and only if B cannot occur without the
occurrence of A.
Example:
Oxygen is a necessary condition
for fire, but not sufficient.
Sufficient
conditions, instead,
are enough to bring about a particular event or property.
A
is a sufficient condition of B if and only if whenever A occurs, B also occurs.
Example:
Sugar is a sufficient
condition for sweetness.
Exercises
Directions:
Label the relationship between the given examples as either:
(1)
Necessary (but NOT sufficient),
(2)
Sufficient (but NOT necessary),
(3)
Neither necessary nor sufficient.
1. Fire is a
______________ condition for oxygen.
2. Striking a
match is a ______________ condition for lighting a match.
3. Sweetness is
a _______________ condition for sugar.
4. Five nickels
is a ___________ condition for twenty-five cents.
5. Blackness is
a _____________ condition for being a raven.
6. Being at
least 15 years of age is a _____________ condition for being 25 years of
age.
7. Mortality is
a _____________ condition for being a human.
8. Yellowness is
a ________________ condition for being a banana.
9. A banana is a
_____________ condition for yellowness.
10. Being a
flower is a _______________ condition for being a rose.
11. Being a bachelor is a _______________ condition for an unmarried adult male.