Definitions On Possibility And Concievability

Question 1

Conceivability

Answer 1

The ability to be though of or mentally grasped
Eg can conceive of what a classroom is like
Can conceive of a giant penguin in our classroom: can grasp what it would actually be like if it happened, and what it would mean
Can’t conceive of a three sided square: can’t be imagined, inconceivable

Question 2

Physical (actual) possibility

Answer 2

Physically (actually) possible- What can occur within our own world due to the laws of physics etc, what could be the case
-Consistent with the laws of nature
-A subset of what is logically possible; whatever is physically possible must be logically possible (but whatever is logically possible isn’t always physically possible)
(Empirical fact level)

Question 3

Metaphysical possibility

Answer 3

Metaphysically possible- Whatever is possible in some possible world, even if it’s not possible in our world
-All the ways the universe might have been
-Often also logically possible (always thought to be)
-But now found we can have claims that are logically possible but not metaphysically impossible
(Logical fact level)

Question 4

Logical possibility

Answer 4

Logically possible- Whatever is not logically contradictory
-Wouldn’t involve a contradiction
-Eg life on mars, blue raspberries= conceivable
-Could be expressed as there is a possible world in which there is blue raspberries
(Logical fact level)

Question 5

Possible worlds

Answer 5

Possible worlds- the way the universe might have been= contingent matter
-Could be possible worlds which differ from actual world in just one way
-Could be other possible worlds which are very different form our own eg different laws of physics etc
Contingent truths= Can change depending on the world eg blue raspberries
Necessary truths= True in all worlds regardless of contingent truths eg mathematics

Question 6

Physical (actual) impossibility

Answer 6

Physically (actually) impossible- What cannot occur due to our laws of physics etc
Eg not physically possible to fly by flapping your arms
-a contingent matter

Question 7

Metaphysical impossibility

Answer 7

Metaphysically impossible- Could not be possible in any possible world
-what couldn’t be the case; inconceivable
Eg water is not H20

Question 8

Logical impossibility

Answer 8

Logically impossible- Whatever is inherently logically contradictory

• There is a contradiction in terms
• Eg a square with 3 sides
• Cannot be true in any possible world