Recently I've been looking into arguments designed to mirror theistic arguments while reaching some atheistic conclusion, such as the non-existence of god or the self-necessity of the universe. They try to use many of the premises of the original theistic argument in reaching their conclusion, designed to make the theist give up that premise to avoid the conclusion. At least one of them is not sound, but I think they are all interesting regardless. Tell me what you think.
Contingency
Atheistic Argument from Contingency
1. If C1 is the cause of some effect E1, then C1 necessitates E1 (a cause produces its effect, that it what makes it the cause of its effect).
2. So every possible world in which C1 obtains is a world in which E1 obtains. [From 1]
3. So the modal status of a cause C1 of some effect E1 must be equivalent to, or less than, the modal status of its effect E1. For suppose that C1 is contingent, so that it obtains in at least one possible world – then E1 also obtains in that world and is therefore at least contingent. Suppose that C1 is necessary, that it obtains in every possible world – then E1 also obtains in each of those worlds and is necessary. Of course, if C1 is impossible, than the modal status of C1 cannot but be equivalent or greater than that of C1. [From 2]
4. The universe is contingent.
5. So the modal status of any cause of the universe is either contingent or impossible. [From 3 and 4]
6. An impossible cause would be absurd.
7. So the modal status of any cause of the universe is contingent. [From 5 and 6]
8. God is a necessary being.
9. So God is not the cause of the universe. [From 7 and 8]
Citation:
An Atheistic Argument from Contingency, by Dace
New Atheistic Argument from Contingency
1. God created the universe (hypothesis).
2. If God created the universe, then he had (sufficient) reason for performing this action.
3. A reason for action is a combination of beliefs and desires – for one to have a reason to act requires that one have beliefs about how reality is, to believe that a particular action would be efficacious in transforming that reality, and to have desires that reality be changed in accordance with that action.
4. So God created the universe because of the beliefs and desires that he had when he chose to create the universe.
5. God is essentially omniscient – that is, in any possible world where God exists, he knows all the truths of that world, and of all possible worlds. He believes all and only those truths.
6. God is essentially omnibenevolent – that is, in any possible world where God exists, he desires the good and only the good.
7. So, for any two possible worlds W1 and W2, if they both contain God, then God has the same beliefs and desires in W1 and W2.
8. God is a necessary being – that is, he exists in all possible worlds.
9. So in every possible world, God has the same beliefs and desires.
10. So in every possible world, God has the same reasons for action.
11. Then in every possible world, God creates the universe.
12. So the universe is a necessary object.
13. But the universe is a contingent object.
14. Therefore, contrary to 1, God did not create the universe.
Citation: Also by Dace on same link.
Kalam
The Kalam Argument Against God
P1: Nothing which exists can cause something which does not exist to begin existing.
P2: Given (1), Anything which begins to exist was not caused to do so by something which exists.
P3: The universe began to exist.
P4: Given (2) and (3), the universe was not caused to exist by anything which exists.
P5: God caused the universe to begin to exist.
C1: Given (4) and (5), God does not exist.
Citation:
I "Kalam" Like I See 'Em, by TheoreticalBull****
Fine-Tuning
Theistic Argument Against Fine-Tuning
1. If theism is true, then divine causation obtains the combination of physical constants which is necessarily capable of sustaining life.
2. If divine causation obtains the combination of physical constants which is necessarily capable of sustaining life, then all facts of the universe are contingent upon God's act of creation.
3. If theism is true, then life can arise under any possible physical condition. (from 1 and 2)
4. If theism is true, then fine-tuning is invalid. (from 3)
Citation:
Iron Chariots on the Fine-Tuning argument, summarizing an argument by Bertrand Russel. I recommend reading the part above the formal syllogism to better understand the argument.
Ontological
Gasking's Proof
1. The creation of the universe is the greatest achievement imaginable.
2. The merit of an achievement consists of its intrinsic greatness and the ability of its creator.
3. The greater the handicap to the creator, the greater the achievement.
4. The biggest handicap to a creator would be non-existence
5. Therefore if we suppose that the universe is the creation of an existing creator, we can conceive a greater being — namely, one who created everything while not existing.
6. Therefore, God does not exist.
Citation: Philosopher Douglas Gasking
Ontological Argument for the Non-Existence of God
1. God is the greatest being conceivable.
2. Non-existence is greater than existence.
3. Therefore god does not exist.
I just made this one up to play off the theme of the subjectivity of greatness.