As Hal's question and my reply remind me, my expectations were still too high. Still, I endeavor to be a little ambitious. That is, I suggest that something positive, although much less than conclusive proof can be drawn from Anselm's argument. I have revised my reply to the last objection (Objection F) accordingly.
The Argument:
(1) God is, by definition, the greatest conceivable being.
(2) Existing is a great making feature, that is, a being that has certain features plus the feature of existing is greater that a being with the same features but without the feature of existing.
(3) God has features but not the feature of existing. (assumed for reductio)
(4) We can conceive of a being, greater than God, such that it has the same features as God plus the feature of existing. (From 2,3)
(5) Therefore, there is a being greater than the greatest conceivable being. (From 1,4)
(6) Therefore, it is not the case that God has features but not the feature of existing. (From 1-5, reductio ad absurdum)
(7) Therefore, it is not the case that God has no features. (From 1,6)
(8.) Therefore, God has the feature of existing, that is, God exists. (From 6,7)
Objections and Replies:
(A) (2) is false. Existing cannot be a feature. Whenever we say of anything that it exists we are not saying anything further about what it is. Reply: There is no reason to think that existing can never be a feature. It is for all we know theoretically possible for something to posess existing as a feature of what it is, even though ordinarily most things do not posess exiting as a feature. Admittedly, to say that something posesses existence as a feature is to say that it necessarily exists.
(B) Even if something could posess existing as a feature, necessary existence is inadequate. It only leads us to conclude that either God exists or that God cannot exist. Reply: It is conceded that necessary existence is inadequate to conclude that God exists. We may suppose that not only is the posession of existing as a feature a great making property but that there is a further feature, call it "Feature E", that explains how God has existing as a feature. Since this is intuitively a great making feature also, God, the greatest conceivable being must have this feature too. And this feature explains why there is a God rather than not.
(C) Feature E, whatever it it, must be something like self-existence, and this is simply incoherent, like something bringing itself into being from non-being, which is impossible. Reply: It is conceded that self-existence is impossible and that Feature E is like self-existence, but it is not conceded that Feature E is self-existence. Like the concept of the infinite, we do not have a clear conception of what Feature E is, and we don't have a proper way of formulating it, but inconceivability and unformulablity are not guides to impossibility. But we can still see that it is a great making feature and that the greatest conceivable being must have it.
(D) No one can have a concept of Feature E. Reply: It is clear that many people are persistently and frequently involved in a form of life and a language game that presupposes having a concept of Feature E in virtue of worshipping God who must not only be seen as necessarily existing but also as possessing this further magnificient trait. Further, there is also the philosophical game based on the hypothesis of the principle of sufficient reason which poses that there is a reason that explains why there is everything that there is and not nothing, which reason also cannot properly be formulated and which must altimately come to rest on Feature E. So it seems that one can have a concept of Feature E.
(E) Without an account of Feature E, the whole argument is question-begging since we have nothing on the table to describe the necessary feature and can only assume it to be available. Further, without already having some positive idea of how such an analysis might go, you could never even know when you have discovered it. Reply: It is conceded that the defender of the argument owes the critic an analysis of Feature E and it is admitted that all that can be offered is a promissory note. However, if the greatest conceivable being exists, He may yet illumine our minds to see what analysis is required even while we have as yet no idea about how to procede to the answer. And in this as well as any other case, we will be better people if we risk assuming that analyses of concepts that we think we may have are available to be found than if we dispair of the possibility of knowing the answer.
(F) Given that response, the definition that God is the greatest conceivable being, and that no non-question-begging evidence is available for any philosophical position, there is no motivation for pursuing an analysis of Feature E since acceptance of belief in God is already sufficiently motivated through prudential grounds. Reply redux: It is conceded that no non-question-begging evidence is available, This is true also of this argument, since it tacitly assumes the debatable premise that conceivability is a test for possibility, so know conclusive public demonstration is possible, even if we had the analysis of Feature E available. Even so, it is at least suggested that having the concept of Feature E in mind makes a difference in the structure of plausibility for a person (or group or tradition or form of life). In particular, it makes the idea something could exist without Feature E being instantiated more implausible. Concepts are firmly grasped and transferable between conceptual reasoners as they are made explicit. Also, showing that a concept is explicable shows that the concept's effect in the plausibility structure is motivated independently of other psychological factors. I suggest that having the concept of Feature F firmly in mind makes theism objectively more plausible and naturalism less so. Since, ex hypothesi, if God exists, the pursuit of truth is important, and since there is no way to break up a stalemate between conflicting perspectives, but we still may provide a personal objective ground for a person to rationally prefer one perspective over another, we have an obligation to truth to pursue and work for the discovery of the analysis of Feature E.
The Argument:
(1) God is, by definition, the greatest conceivable being.
(2) Existing is a great making feature, that is, a being that has certain features plus the feature of existing is greater that a being with the same features but without the feature of existing.
(3) God has features but not the feature of existing. (assumed for reductio)
(4) We can conceive of a being, greater than God, such that it has the same features as God plus the feature of existing. (From 2,3)
(5) Therefore, there is a being greater than the greatest conceivable being. (From 1,4)
(6) Therefore, it is not the case that God has features but not the feature of existing. (From 1-5, reductio ad absurdum)
(7) Therefore, it is not the case that God has no features. (From 1,6)
(8.) Therefore, God has the feature of existing, that is, God exists. (From 6,7)
Objections and Replies:
(A) (2) is false. Existing cannot be a feature. Whenever we say of anything that it exists we are not saying anything further about what it is. Reply: There is no reason to think that existing can never be a feature. It is for all we know theoretically possible for something to posess existing as a feature of what it is, even though ordinarily most things do not posess exiting as a feature. Admittedly, to say that something posesses existence as a feature is to say that it necessarily exists.
(B) Even if something could posess existing as a feature, necessary existence is inadequate. It only leads us to conclude that either God exists or that God cannot exist. Reply: It is conceded that necessary existence is inadequate to conclude that God exists. We may suppose that not only is the posession of existing as a feature a great making property but that there is a further feature, call it "Feature E", that explains how God has existing as a feature. Since this is intuitively a great making feature also, God, the greatest conceivable being must have this feature too. And this feature explains why there is a God rather than not.
(C) Feature E, whatever it it, must be something like self-existence, and this is simply incoherent, like something bringing itself into being from non-being, which is impossible. Reply: It is conceded that self-existence is impossible and that Feature E is like self-existence, but it is not conceded that Feature E is self-existence. Like the concept of the infinite, we do not have a clear conception of what Feature E is, and we don't have a proper way of formulating it, but inconceivability and unformulablity are not guides to impossibility. But we can still see that it is a great making feature and that the greatest conceivable being must have it.
(D) No one can have a concept of Feature E. Reply: It is clear that many people are persistently and frequently involved in a form of life and a language game that presupposes having a concept of Feature E in virtue of worshipping God who must not only be seen as necessarily existing but also as possessing this further magnificient trait. Further, there is also the philosophical game based on the hypothesis of the principle of sufficient reason which poses that there is a reason that explains why there is everything that there is and not nothing, which reason also cannot properly be formulated and which must altimately come to rest on Feature E. So it seems that one can have a concept of Feature E.
(E) Without an account of Feature E, the whole argument is question-begging since we have nothing on the table to describe the necessary feature and can only assume it to be available. Further, without already having some positive idea of how such an analysis might go, you could never even know when you have discovered it. Reply: It is conceded that the defender of the argument owes the critic an analysis of Feature E and it is admitted that all that can be offered is a promissory note. However, if the greatest conceivable being exists, He may yet illumine our minds to see what analysis is required even while we have as yet no idea about how to procede to the answer. And in this as well as any other case, we will be better people if we risk assuming that analyses of concepts that we think we may have are available to be found than if we dispair of the possibility of knowing the answer.
(F) Given that response, the definition that God is the greatest conceivable being, and that no non-question-begging evidence is available for any philosophical position, there is no motivation for pursuing an analysis of Feature E since acceptance of belief in God is already sufficiently motivated through prudential grounds. Reply redux: It is conceded that no non-question-begging evidence is available, This is true also of this argument, since it tacitly assumes the debatable premise that conceivability is a test for possibility, so know conclusive public demonstration is possible, even if we had the analysis of Feature E available. Even so, it is at least suggested that having the concept of Feature E in mind makes a difference in the structure of plausibility for a person (or group or tradition or form of life). In particular, it makes the idea something could exist without Feature E being instantiated more implausible. Concepts are firmly grasped and transferable between conceptual reasoners as they are made explicit. Also, showing that a concept is explicable shows that the concept's effect in the plausibility structure is motivated independently of other psychological factors. I suggest that having the concept of Feature F firmly in mind makes theism objectively more plausible and naturalism less so. Since, ex hypothesi, if God exists, the pursuit of truth is important, and since there is no way to break up a stalemate between conflicting perspectives, but we still may provide a personal objective ground for a person to rationally prefer one perspective over another, we have an obligation to truth to pursue and work for the discovery of the analysis of Feature E.
The Gnu
"I'll so offend to make offense a skill redeeming time when men least think I will." -- Henry IV
"Hear you nothing that I say?" -- Yoda
