Possibility and necessity

Question 1

modal facts

Answer 1

obtain in addition to the basic facts about what things happen

Question 2

relations between necessity and possibility

Answer 2

P is necessary just in case not-P is not
possible

P is possible just in case not-P is not
necessary

Question 3

epistemic use of `possible’

Answer 3

it concerns someone’s knowledge - something is possible when it is compatible with your knowledge - eg. it’s possible that a certain football team won

Question 4

natural necessity

Answer 4

Some condition is naturally necessary just in case its happening is a consequence of the laws of
nature - eg. It is a natural necessity that nothing travels faster than the speed of light

Question 5

natural possibility

Answer 5

its happening is compatible with the laws of nature

Question 6

laws of nature

Answer 6

The laws of nature are things that the special sciences aim to discover and describe

Question 7

The Regularity Theory of Lawhood

Answer 7

It is a law that all Fs are Gs just in
case all Fs are Gs

problems:
The regularity account seems to miss the necessity that laws impose

Laws, it seems, explain why certain things happen, but it would seem that mere regularities are explained by their instances

Most worryingly it would seem that not all true regularities are genuine candidates for being laws

Question 8

An Example: Let N be the largest number of people that ever have or will attend a dinner party

Answer 8

Then it’s a true regularity that every dinner party has at most N guests
but it’s not a law that there has to be N guests at a dinner party

Question 8

universals

Answer 8

could make true regularities into laws

Universals are properties that can be shared by different objects

According to this view for it to be a law that all Fs are G just is for there to be universals Fness and Gness, and for these to be be related in a particular way

Question 8

necessitation

Answer 8

According to this view for it to be a law that all Fs are G just is for there to be universals Fness and Gness, and for these to be be related in a
particular way

Thus, it’s a law that all Fs are Gs just in case Fness necessitates Gness

Consider the first objection: Mere regularities miss the necessitating force of laws

On this account, the necessitation comes from the relation that relates the relevant universals

Next consider the second objection: The laws explain their instances.

But the fact that Fness necessitates Gness, can, at least in principle, explain why this particular F is G,
without this leading to a circular explanation

Finally, consider the third objection: Not all true regularities are candidates for being laws

For even if it is true that all Fs are Gs, one need not say that Fness necessitates Gness - if we appeal to a special relation between universals we can provide an account of why
certain regularities are laws and why certain regularities are not. eg. N number of people at a dinner party