Modal Ontological Argument

Question 1

What is modal logic

Answer 1

logic of modalities - necessity/possibility

Question 2

what is neccesary p in modal logic

Answer 2

P is true in every possible world

Question 3

what is a possible world

Answer 3

state of affairs for which every other state of affairs is either included or excluded

one possible world is the actual world (whatever is the case)

Question 4

what are state of affairs

Answer 4

possible way things could be

some obtain some do not (I am not currently running but I could be = does not obtain)

Question 5

what is possibly P in modal logic

Answer 5

p is true in at least one possible world

Question 6

what is the accessibility relation

Answer 6

necessities don’t vary across worlds

Question 7

de dicto vs de re modality

Answer 7

de dicto: of a proposition (2+2=4)

de re: of a being (neccesary being)

Question 8

what is the modal ontological argument

Answer 8

1) modal logic
2) its possible that god exists
3) god exists if and only if it is necessary that God exists
4) hence, it is possible that it is necessary that god exists
5) hence it is necessary that god exists

Question 9

what is Plantinga’s modal ontological argument

Answer 9

1) there is a possible world in which an unsurpassable greatness exists
2) it is necessarily true that ‘an unsurpassable greatness exists if and only if it is has maximal excellence in every possible world’
3) ‘whatever has maximal excellence is omnipotent, omniscient and omnibenevolent’ is true
4) hence, a being that possesses unsurpassable greatness is necessarily true in every world

Question 10

what is the significance of S5 Modal logic

Answer 10

S5 modal logic implies that a necessity is necessary in all possible worlds