Anyone can do a guide for me? I wanna study logic for understand mõdal logic

[icy whale]

I do not understand so much about logic but i wanna understand this:
Ax. 1. P(φ) ∧ □ ∀x (φ(x) → ψ(x)) → P(ψ)
Ax. 2. P(¬φ) ↔ ¬P(φ)
Th. 1. P(φ) → ◇ ∃x φ(x)
Df. 1. G(x) ↔ ∀φ (P(φ) → φ(x))
Ax. 3. P(G)
Th. 2. ◇ ∃x G(x)
Df. 2. φ ess x ↔ φ(x) ∧ ∀ψ (ψ(x) → □ ∀y (φ(y) → ψ(y)))
Ax. 4. P(φ) → □ P(φ)
Th. 3. G(x) → G ess x
Df. 3. E(x) ↔ ∀φ (φ ess x → □ ∃y φ(y))
Ax. 5. P(E)
Th. 4. □ ∃x G(x)
(I am 8th grade and i dont understand so much about and i know the St Anselm argument)

[errant meadow]

is that arabic?

[icy whale]

💀

Its mõdal logic

A ontological argument for proof that god exisits

[crisp pond]

What is the context. What is P, what is phi, what is G, what is ◇ what is E

[errant meadow]

oh I see

[icy whale]

I dont know so much

But its like the St Anselm argument but "positive property"

[errant meadow]

A upside down means “any”

[icy whale]

I wanna a guide for study this

[crisp pond]

The symbols have no meaning without any context

Do you have a link or source?

[icy whale]

Its about god existence

[crisp pond]

That is not enough context

[icy whale]

Do you know about the St. Anselm argument?

[crisp pond]

No

[icy whale]

Ontological argument*

Search, its very cool. But Kant "refute"

[crisp pond]

I can't explain the argument without the context, but ill explain some stuff

Ax -> Axiom
Th -> Theorem
Df -> Definition

P -> need context
phi -> need context
psi -> need context
G -> need context
E -> need context
ess -> need context

◇ -> non standard notation, need context
□ -> non standard notation, need context
∀ -> For all
x -> variable
→ -> implies (if ... then ...)
↔ -> if and only if
∧ > and

[icy whale]

Oh

Ok then

How i study?

[unkempt flax]

if you're interested, forallx is a online open source textbook for learning propositional logic, first order logic and modal logic

https://forallx.openlogicproject.org/

[unkempt flax]

and yes, you need to learn the three in sequence to understand modal logic

[unkempt flax]

but, I personally extremely doubt that this is a "real" proof of god's existence

knowing the way modal logic works, they probably assumed that few things, and proved that if those things were true, then "god exists"

some of those assumptions usually look like "everything has a cause" or "time has a beginning"

[crisp pond]

Also when studying philosophical arguments I think it is pointless to study arguments using symbolic logic. The argument can be given just aswell in natural language

[unkempt flax]

which are kinda stupid ontological apologist arguments imo lmao

[crisp pond]

Of course you need to know logic to understand why certain statements follow from others but it is not necessary to represent everything in abstract symbols

[unkempt flax]

point is, if you want to understand this purely to make sure god exists, I'm telling you right now understanding this proof will not give you any new answers nor change anything that you already didn't believe in

[icy whale]

5 ways ahh 😭😭😭

[icy whale]

Ok, but i wanna study about

For me the best ontological argument is platinga argument

[unkempt flax]

sure

and you can study that without needing to waste time studying modal logic

[icy whale]

Really?

But will be good i study modal logic?