This is one of the most complex issues there is,especially Hartshorne's version which I use,or one similar to his. On Victor Reppert's Dangerous Idea Blog I found our old friend Stardust makimng the claim that there are no valid arguments for God. As it turns out he didn't know what valid meant. He didn't know in logic it refers to the technical presentation of the argumet Arguments must be both valid and sound, soundness refers to truth. After dancing around that for a bit I decided to just challenge him to debate the modal argument.
1. God is either necessary or impossible.
2. God can be conceived without contradiction.
3. Whatever can be conceived without contradiction is not impossible.
4. God is not impossible.
5. God is necessary.
6. That God's existence is necessary is a good reason to believe that God is real.
7. Therefore, believe in God's reality is warranted.
Notice I don't say god's "existence," Those of you who follow my blog and have seen my discussion of Tillich will understand this, for the rest of you it';snot important. Notice also that I argue in terms of warrant and not proof. Both Hartshorne and Plantinga refuse to contend they have prove the existence of God but Plantingia argues that the nodal argument is warrant for belief.
"IF God exists THEN it is logically necessary that(God exists)"Only in the tautological sense that this statement applies to all existent things. If a thing exists then it is necessary that it exists since it is existent. That makes god nothing special.
wrong, you are not paying attention ,What is being said is that there are only two possibles regarding God's modal status, either necessary or impossible. In other words no middle ground, if God exists he must exist he can't be a maybe, he could not have failed to exist, if there is a God there had to be a God. The only alternative is that if God does not exist it's impossible that God could have existed God either exists and it is necessary that he does or he doesn't exist and if so it's because he could not exit.
If you mean some notion of alternative possibilities that makes god special necessarily then no, one can speculate that something gave rise to god, god's god, but maybe god's god died, though previously greater than god, but now dead, so now god exists.
Nope doesn't work that way. God has to be eternal or he can't be at all., he could not have a cause.If God exists he exists as a necessity, A necessity doesn't have a cause,if it did it would be contingent.
The speculative alternative formulations are unbounded, hence the assertion of necessity is false.
wrong modal operators are not "unbounded." Yes there is a limitless field of speculation concerning God but NOT where modal operators are concerned.
Fail from the git go, but then, you did not fully define your terms so you might think you have some definitional alternatives to these failings.
Line 3 is a non-sequitur. Just because we can imagine something that does not contradict itself as we imagine it does not mean the reality of the universe can possibly accommodate a realization of that fantasy.
p3 is the lynch pin of the thing, it's anything but irrelevant, the argent turns upon it.
[This argument is about logic and it came in the discussion when we where arguing about validity.So how constriction is regarded in logic really matters.The concept of impossibility is about logical contradiction. Since impossibility is obtained by being illogicality contradictory the lack of contradiction means possibility,]
Hartshorne is asserting that mere fantasy is sufficient to allow for external realization. He obviously has a hard time separating fantasy from reality, but that is typical of the theistic mind.
No logician in the world thinks that, he is not saying that,
[He's equating using logic to Establishment of truth by logic with fantasy because he thinks empiricism is the only form of knowledge. As iv say below his position of empiricism as the only true knowledge cannot be proved empirically, He has to use logic to establish probability then to connect probability to empiricism.We know logic can tell us some things about the world. For example we don't have to go look for square circles we know there are none because the concept contradicts itself. For positive understanding of truth content thorough logic see below.]
The whole argument hinges on thinking makes it so, an absurd notion. Why anybody takes this nonsense at all seriously is truly a wonderment for me.
It's so sophomoric to reduce the work of a recognized great thinker to "he thinks thinking makes it so." No he did not think that.He thought that the ontological principle is true. in other words if the terms of a proportion spell out the truth content of the proposition when understood then we have to assume the truth of the argument if the prepositions are valid.
Tillich's example of this principle is that the principle of truth cannot be disputed without admitting to the validity of the principle. One can only say the principle is false if one is willing to admit that truth exists and this principle departs from it, Thus to dispute the truth of truth is to accept the proportion that truth exists. Truth can never be disputed as truth or as sound based upon a logical denial. This is Duane Olson explaining Tillich's view:
The indubitability of the norm of truth is shown by a reductio argument regarding the process of knowing. In different places and in different ways Tillich points out that denial and doubt in knowing presuppose the norm of truth.[17 in the article] I want to systematize Tillich’s reductio argument at this point to show that all major theoretical postures presuppose this norm.
We can imagine four major postures taken by a subject to any theoretical judgment. One could affirm the judgment, claiming it corresponds with reality; one could deny the judgment, claiming it does not correspond; one could doubt, question, and debate the judgment; or one could claim a decision cannot be made about the judgment. All of the options presuppose the subject’s ability to apply a correspondence-norm, or norm of truth. Certainly one must apply a norm to affirm a judgment. One must also apply a norm, however, to deny a judgment. Any negative judgment presupposes and lives from the positive bearing of a norm of truth by the subject. One cannot deny that a judgment corresponds to reality without presupposing the subject’s ability to make judgments about reality. Doubting, questioning, or debating a judgment presuppose a norm of truth as well. One could not debate the veracity of a judgment without presupposing the capacity in the debaters to determine that veracity. Doubting or questioning a judgment is only meaningful under the presupposition of a norm that gives validity to that questioning and doubting. Finally, the claim that one cannot know whether a judgment is true presupposes the bearing of a norm to determine how or why a decision cannot be made.
It is important to note that the argument for a correspondence-norm, or norm of truth, is on a different level than arguments about the specific nature of the correspondence between subject and object. The correspondence itself may be conceived in terms of naïve realism, idealism, or a multitude of positions in between. Every theory about the nature of the correspondence, however, relies on the presupposition of a correspondence-norm that would make it possible to formulate, and affirm, deny, debate, or declare uncertain that theory. Put differently, the theory of the specific nature of the correspondence between subject and object is another field of knowledge that is subject to the ultimate criterion of knowledge, which is what is disclosed in the idea of a correspondence-norm.
To claim that the capacity to apply a norm is indubitable is the same thing as saying the subject bears an indubitable awareness of truth. In other words, when one analyzes the major postures toward judgments and shows how a norm of truth is presupposed as something borne by the subject in every posture, one is pointing out an awareness of truth the subject has, though it is something the subject may overlook, especially in doubting or denying particular truths. Through the reductio argument, one focuses attention on the fact that the subject bears a norm of truth, thus raising it to conscious awareness. I speak more below about the character of this awareness, but for now I simply affirm something Tillich presupposes, which is the identity between the affirmation that the subject bears a norm of truth and the subject’s awareness of this norm.
Heartshorne's version is the evocation of necessity with the possibility of God. In other words necessity is such that if X is necessary and possible the possibility of X means it must exist because it can't be merely possible if it's necessary. That's where no p3 comes in. The only two possibilities for go are necessary and impossible, If God is possible hes not impossible and thus must be necessary. This is all guaranteed by the nature of modal operators. Modal operators are words that disclose the modes of being; hence"modal" logic. Modes of being are states such as necessity or contingency. Donald Wayne Viney and George W. Shields document:
Hartshorne considered the empiricist position regarding the ontological argument as the least tenable. The second premise says, colloquially, if God is so much as logically possible, then it must be the case that God exists. Hartshorne calls this “Anselm’s principle,” or more forcefully, “Anselm’s discovery.” The discovery is that God, as unsurpassable, cannot exist with the possibility of not existing. Put differently, contingency of existence is incompatible with deity. Anselm’s formula that God is “that than which nothing greater can be conceived” means, among other things, that any abstract characteristic for which something greater can be conceived cannot properly be attributed to deity. 
Dusty also tried to confuse soundness with empirical knowledge, after I pointed out the distinction between sound and valid, That is not the case either, its not abouit empirical evidence we are still dealing in logical argument. Here is the distinction on these terms:
I. Truth, Validity, and Soundness: probably the three most important concepts of the course.
A. First, let us briefly characterize these concepts.
1. truth: a property of statements, i.e., that they are the case.
2. validity: a property of arguments, i.e., that they have a good structure.
(The premisses and conclusion are so related that it is absolutely impossible for the premisses to be true unless the conclusion is true also.)
3. soundness: a property of both arguments and the statements in them, i.e., the argument is valid and all the statement are true.
Sound Argument: (1) valid, (2) true premisses (obviously the conclusion is true as well by the definition of validity).
B. The fact that a deductive argument is valid cannot, in itself, assure us that any of the statements in the argument are true; this fact only tells us that the conclusion must be true if the premisses are true.
Empirical evidence is not the issue, Most atheists on the net make the assumption that empiricism is the only real form of knowledge and logic is just made up and doesn't prove anything this something no one can prove with any empirical standard.I dom't argue that i can prove the existence of God. The issue originally was validity,I shewed the argument here is valid, It's also sound because the preemies are true and the argument is valid. Does that prove god is real? No but it's a good reason to think he is, Therefore belief in god is warranted,
 Donald Wayne Viney and George W. Shields "Charles Hartshorne Theistic and Anti-theistic Arguments," Internet Encyclopedia of Philosophy: a Peer Reviewed Academic Resource. Internet online resource. no date indicated, URL: http://www.iep.utm.edu/hart-t-a/#H1 (accessed 1/15/17).
Donald Wayne Viney
Pittsburg State University
U. S. A.
George W. Shields
Kentucky State University
U. S. A.
Duane Olson, “Pual Tiillich and the Ontological Argument,” Quodlibet Journal vol. 6, no 3, July-sep 2004, online journal, URL: http://www.quodlibet.net/articles/olson-tillich.shtml visited 8/4/10
Olson has two foot notes in this quotation which are important to examine:
1) “In one of the more significant recent monographs on Tillich’s thought, Langdon Gilkey flatly states “[Tillich] denied that an argument for the transcendent power and ground of being was possible” (Gilkey on Tillich (Wipf and Stock Publishers, 2000), 105). Gilkey never discusses Tillich’s use of the traditional arguments.” (2) “In his detailed and extensive volume on the ontological argument, Graham Oppy mentions Tillich’s name only once in the literature review, and he never analyzes any of Tillich’s statements (Ontological Arguments and Belief in God (Cambridge: Cambridge University Press, 1995), 275). To Oppy’s credit, he discusses a type of argument to which Tillich’s is related. I comment on Oppy’s analysis of this argument in the final section of this paper.”
 Donald Wayne Viney and George W. Shields "Charles Hartshorne Theistic and Anti-theistic Arguments," op cit
 Introduction to Logic, PLE