One morning an irate C-Span viewer called in to say that he prayed to the living God, not to the mythical being, Allah, to whom Muslims pray. The C-Span guest made a standard response, which is correct as far as it goes, namely, that ‘Allah’ is Arabic for God, just as ‘Gott’ is German for God. He suggested that adherents of the three Abrahamic religions worship the same God under different names. No doubt this is a politically correct thing to say, but is it true? The intertranslatability of the different names for God in different languages does not obviously prove real identity of reference. How so?
The underlying issue concerns the mechanism of reference. How do linguistic expressions attach or apply to extralinguistic entities? How do words grab onto the world? It is reasonable to hold, with Frege, Russell, and many others, that reference is routed through, and determined by, sense: an expression picks out its object in virtue of the latter’s satisfaction of a description associated with the referring expression, a description that unpacks the expression’s sense. If we think of reference in this way, then ‘God’ refers to whatever entity, if any, that satisfies the definite description encapsulated in ‘God’ as this term is used in a given linguistic community.
Now consider two candidate definite descriptions.
D1: ‘the unique x such that x is omnipotent,omniscient, omnibenevolent, and created the world ex nihilo.’
D2: ‘the unique x such that x is omnipotent, omniscient, omnibenevolent, created the world ex nihilo, and is triune.’
Suppose that reference is not direct, but routed through sense, or mediated by a description, in the manner explained. If (D1) is the description that explicates (‘unpacks’) the sense of ‘God,’ then Jews, Christians, and Muslims refer to the same entity when they use ‘God’ (or its equivalents in Hebrew and Arabic). But if (D2) is the description that explicates the sense of ‘God,’ then Jews, Christians, and Muslims do not refer to the same entity. This is because it is no part of the sense of ‘God’ for a Jew or a Muslim that God be triune, i.e., be one God in three divine persons. On the contrary, the Jewish and Muslim emphasis on the transcendence and radical unity of God entails for them the denial of any trinitarian structure in God.
Since (D2) comes closer than (D1) to a full unpacking of the sense of ‘God’ as Christians use this term, it follows that Christians and Muslims do not refer to the same entity. They do not refer to, or worship, the same God for the simple reason that their conceptions of God – conceptions built into the very sense of ‘God’ – are mutually exclusive.
Now what about the Eastern Orthodox? They too are trinitarians, but they reject the filioque clause: they deny that the Holy Spirit proceeds from the the Father and the Son, holding instead that the Holy Spirit proceeds from the Father alone. (Imagine chopping someone’s head off over a theological nicety such as this.) So do the Roman Catholics and the Eastern Orthodox refer to the same entity when they say ‘God’? No, if reference is routed through sense, and if the filioque clause is part of the very sense of what the Eastern Orthodox mean when they say ‘God.’
A further wrinkle. I would say that any God worthy of worship must be ontologically simple, while Alvin Plantinga – no slouch of a philosopher – would reject the very idea of divine simplicity as incoherent. So when he and I use ‘God,’ are we referring to the same entity?
I hope you are beginning to see how much is hidden behind the facile remark that Jews, Christians, and Muslims worship the same God. If ‘God’ is a logically proper name whose meaning is exhausted by its reference, a Kripkean rigid designator, then perhaps the above difficulties can be circumvented. But others arise from the fact that we seem to have no access to God except via our conceptions of God.
Let me extract a metaphilosophical moral from this. Almost any foreground consideration leads inevitably into a philosophical labyrinth. In this sense, philosophy is entirely natural: philosophers do not create puzzles where there are none; they simply uncover the puzzles that are already there.
But there are those who cannot understand this. Among them we find positivists and ordinary language 'philosophers.'