Patrick Grim gives something like the following argument for the impossibility of divine omniscience. What I know when I know that
1. I am making a mess
is an indexical fact that no one else can know. At most, what someone else can know is that
2. BV is making a mess
or perhaps, pointing to BV, that
3. He is making a mess.
Just as no one except BV can refer to BV by tokening the first-person singular pronoun, no one except BV has access to the indexical fact that, as BV would put it to himself, I am BV. Only BV is privy to this fact; only BV knows himself in the first-person way. Now an omniscient being knows everything that can be known. Although I am not omniscient, there is at least one proposition that I know — namely (1) — that is not known by any other knower, including an omniscient knower. So an omnisicent being is impossible: by its very definition it must know every fact that can be known, but there are indexical facts that it cannot know. God can know that BV is making a mess but he cannot know what I know when I know that I am making a mess. For any subject S distinct from God, the first-person facts appertinent to S are inaccessible to every mind distinct from S, including God's mind. That is what I take to be Grim's argument.
I suppose one could counter the argument by denying that there are indexical facts. But since I hold that there are both indexical propositions and indexical facts, that response route is not available to me. Let me see if I can respond by making a distinction between two senses of 'omniscience.'
A. X is omniscient1=df X knows every fact knowable by some subject or other.
B. X is omniscient2 =df X knows every fact knowable by some one subject.
What indexical facts show is that no being is or can be omniscient in the first sense. No being knows every indexical and non-indexical fact. But a failure to know what cannot be known does not count against a being's being omniscient in a defensible sense of this term any more than a failure to do what cannot be done counts against a being's being omnipotent. A defensible sense of 'omniscience' is supplied by (B). In this second sense, God is omniscient: he knows every fact that one subject can know, namely, every non-indexical fact, plus all facts pertaining to the divine subjectivity. What more could one want?
Since no being could possibly satisfy (A), (A) is not the appropriate sense of 'omniscience.' Compare omnipotence. An omnipotent being cannot be one who can do just anything, since there are both logical and non-logical limits on what any agent can do. Logical: God cannot actualize (create) an internally contradictory state of affairs. Non-logical: God cannot restore a virgin. So from the fact that it is impossible for God to know what is impossible for any one being to know, it does not follow that God is not omniscient.
To sum up. There are irreducible first-personal facts that show that no being can be omniscient in the (A)-sense: Patrick Grim's argument is sound. But the existence of irreducible first-personal facts is consistent with the truth of standard theism since the latter is committed only to a being omniscient in the (B)-sense of 'omniscience.'
Dr. Vito Caiati occasioned in me a new thought the other day: that divine omniscience might require divine incarnation. The gist of the thought is as follows. If God is all-knowing, then he possesses not only all knowledge by description, but also all knowledge by acquaintance. But it is not easy to see how God in his disincarnate state could have all or any knowledge by acquaintance of beings whose subjectivity is realized in matter. And this for the simple reason that if God is a pure spirit then his subjectivity is real without being realized in matter.
One could know everything there is to know objectively about bats but still not know subjectively, 'from the inside,' what it is like to be a bat in Thomas Nagel's sense. Objective omniscience is compatible with subjective nescience. To know what it is like to be a bat I would have to be one: I would have to have the physiological constitution of a bat. And so for God to know what it is like to be a man dying on a cross God would have to be a man dying on a cross. To have objective knowledge of every aspect of dying on a cross is not to experience dying on a cross. That's the rough idea. It has interesting and troubling consequences which I didn't pursue on Saturday night. So I am pleased to hear from Jacques.
Jacques writes,
I agree that God has to become a human being in order to know everything. But, as you say, this seems to lead to further problems. Here are two things that come to mind.
First, there would be the same problem with respect to every sentient being. God has to be one of us in order to know certain perspectival or subjective facts about us. But God also has to be a bat or a beetle, for the same reason, if God is to be truly omniscient.
It seems so.
But in addition, it's not enough for omniscience that God has been incarnated once as a certain type of being. After all, that would mean only that God knows what it's like to have been that human being–a male one, living in the Roman empire, etc. Surely God also needs to know what it's like to be a woman, or a Mayan, or whatever. And also needs to know what it's like to be me as opposed to you, and you as opposed to me. Does this mean that believing in an omniscient God rationally supports some kind of Hindu-ish or pantheistic theory over Christianity? (Or does it mean that Christianity properly understood implies that God is every single one of us, and every bat and beetle?)
This is much less clear. You and I are two numerically different human beings, but I don't need to be you in order to know what it is like to be you. Despite the privacy of experience, most if not all of our sensory qualia are similar if not qualitatively identical. Lacking the special powers of Bill Clinton, I can't feel your pain: I cannot live through numerically the same pain experiences you live though when you are in some definite kind of pain, such as non-migraine headache. Your experiencings are in your psyche; mine are in mine. But I know what it is like when you have a headache since the subjective qualitative features of the experiencings are the same or very similar. What makes this possible is that we are animals of very similar physiological constitution. I suspect that sensory qualia are universals of a sort.
I am not a woman and I so I don't quite know what it is like to experience menstrual cramps. But I know what muscle cramps are like, and so I have some basis for empathy with the distaff contingent of child-bearing years.
And so I would not go so far as to say that for God to know what it is like to be a human, he must be or become every human. It suffices for him to become a human. Nor is it necessary that he become a woman for him to know what it is like to be a woman.
But then there is this consideration:
Is there something it is like to be me, this particular person, numerically different from every other person? Sometimes I have the strong sense that there is. Call it one's irreducible haecceity (thisness) or ipseity (selfness). It is irreducible in that it cannot be reduced to anything repeatable or multiply exemplifiable or anything constructed out of repeatable or multiply exemplifiable elements. This is a sort of quale that I alone have and experience and that no one distinct from me could have or experience. We are all unique, but each of us has his own uniqueness 'incommunicable to any other' as a scholastic might say. I sometimes have the sense that each of us is uniquely unique as a person, as a subject in the innermost core of his subjectivity. And sometimes it seems that I know what it is like to be this uniquely unique person, absolutely irreplaceable and (therefore?) infinitely precious and of absolute worth.
If God exists, he is super-eminently uniquely unique and we, who are made in his image and likeness, are derivatively uniquely unique.
Trouble is, this notion of a uniquely unique haecceity tapers off into the mystical. For my thisness or your's or anything's is ineffable. It cannot be conceptually articulated or put into language. Individuum ineffabile est as a medieval Aristotelian might say. Is the ineffable nonexistent because ineffable? That was Hegel's view. Or is the ineffable existent despite being ineffable? That was the Tractarian Wittgenstein's view: Es gibt allerdings das Unaussprechliche. One cannot eff the ineffable. Does this mean that it is not there to be effed? Or does it mean that effing is not the proper mode of access to the existent ineffable? I incline in the latter direction.
Now suppose that each person at the base of his subjectivity is uniquely unique and is acquainted with his own irreducible haecceity and ipseity. How could God know anyone's haecceity? He can't know it objectively, and to know my haecceity subjectively, as I know it, God would have to be me. This leads on to the heretical thought that for God to be all-knowing, he would have to be every sentient being, as Jacques appreciates.
Second, it seems that having all objective knowledge precludes subjectivity and vice versa. While incarnated as a particular man, with a perspective and personality, God was not simultaneously aware of all objective facts. That kind of awareness would seem to make it impossible to have a perspective and a personality. So is true omniscience impossible? Either you know everything objective, or you know only something objective and only something subjective. I don't mind this result too much. I have no strong intuition that omniscience is possible. But then what should a Christian or other theist believe about God's knowledge?
A God's eye view is a View from Nowhere (to allude to a title of one of T. Nagel's books.) An incarnate God would have to have a definite perspective and personality. But then he could not be objectively omniscient. If, on the other hand, he were objectively omniscient, then he could not be incarnate. That seems to be what Jacques is saying.
It might be replied that that Jesus qua God is objectively omnisicent but subjectively nescient, but qua man is objectively limited in knowledge but has knowledge of qualia. If that makes sense, then we could say that an incarnate God knows more than the same God aloof from matter. For then the incarnate God knows everything the disincarnate God knows plus what it is like to be a man, and by analogy what it is like to be a cat or a dog or any sentient being sufficiently similar in physiological make-up to a man.
Is true omniscience possible? If true omniscience requires knowing everything there is to know, both objectively (by description) and subjectively (by acquaintance), then true or full omniscience is impossible, i.e., no one person could be fully omniscient. What then should a Christian theologian say?
He could perhaps say this: God is omniscient in that he knows everything that it is possible for any one person to know. Now it is not possible that any one person know everything both objectively and subjectively. Therefore, it is no restriction of God's omniscience that he does not know everything.
Could an eternal God know what time it is? Presumably not. Could God be both omniscient and ignorant with respect to future contingents? Why not? God knows whatever it it possible to know; future contingents, however, are impossible for anyone to know.
It is like the situation with respect to omnipotence. It is no restriction of God's omnipotence that he can do only what it is logically possible to do. God is powerless to restore a virgin. But that's nothing against the divine omnipotence.
Tony Flood has gone though many changes in his long search for truth. He seems to have finally settled down in Van Til's presuppositionalism. Tony writes,
God, the cosmos, and a plurality of minds other than one’s own are in the same epistemological boat. [. . .] To be skeptical about one but not the other two is arbitrary. Our innate predisposition to be realistic about all three is divinely written “software” that informs our cerebral “wetware.”
I wish I could accept this, but I don't, and I believe I have good reasons for my non-acceptance.
By "in the same epistemological boat," Flood means that God, the physical universe, and other minds are all on a par in respect of dubitability. No one of them is more open to reasonable doubt than the other two, and none of them is open to reasonable doubt. Therefore, one can no more reasonably doubt the existence of God than one can doubt the existence of other minds. Atheism is on a par with solipsism in point of plausibility.
And bear in mind that by 'God' here is meant something very specific, the triune God of Christian theism, the God of the Bible as understood by Van Til and Co. It is one thing to argue — and it can be done with some plausibility — that the validity of all reasoning about any subject presupposes the existence of an omniscient necessary being. It is quite another to argue that the presuppositum must be the God of Christian theism as the latter is expounded by a Calvinist!
Now I concede that doubts about the external world and the the reality of other minds are hyperbolic, and if taken as genuine doubts, as opposed to thought experiments deployed in an epistemology seminar, unreasonable. No one really doubts the existence of rocks or other minds. Not even Bishop Berkeley doubts, let alone denies, the existence of rocks, the tree in the quad, and suchlike. This is why it is perfectly lame to think that Berkeley's idealism can be refuted by kicking a stone. (See Of Berkeley's Stones and the Eliminativist's Beliefs and Argumentum ad Lapidem?)
The hyperbolic skepticism of Descartes' dream argument and its latter-day brain-in-the-vat incarnations are methodological tools of the epistemologist who seeks to understand how we know what we know, and what it is to know what we know. A philosopher who wonders how knowledge is possible may, but need not, and typically does not, deny or have any real doubt THAT knowledge is possible. For example, I may be firmly convinced of the existence of so-called abstract objects (numbers, sets, propositions, uninstantiated properties, etc.) but be puzzled about how knowledge of such entities is possible given that there is no causal interaction with them. That puzzlement does not get the length of doubt or denial. The same holds, mutatis mutandis, for knowledge of the past, knowledge of other minds, and knowledge of the external world.
My point, then, is that (i) practically no one has real doubts about the existence of the external world or the existence of other minds, and that (ii) it would not be reasonable to have such doubts. But (iii) people do have real doubts about the existence of the God of Christian theism, and (iv) it is not unreasonable to have such doubts. The various arguments from evil, and not just these, cast reasonable doubt on Christian theism.
One type of real doubt is an 'existential' doubt, one that grips a person who succumbs to it, and induces fear and perhaps horror. There are those who lose their faith in God and suffer in consequence. They experience a terrible sense of loss, or perhaps they fear that they have been duped by crafty priests who exploited their youthful innocence and gullibility to infect them with superstitious nonsense in order to keep the priestly hustle going. One can lose one's faith in God, and many do. No one loses his faith in the external world or in other minds. And this for the simple reason that there was no need for faith in the first place.
I believe I have said enough to cast serious doubt on, if not refute, the idea that God, the the cosmos, and other minds are are in the same epistemological boat. That's a boat that won't float.
If we say God cannot create himself since this implies a contradiction (God existing prior to himself to act on himself), how can we say God does anything with regard to himself?
For instance, we say God knows himself. But how is this possible, seeing as God would need to first exist, in order to know himself? Knowledge is a relation in the mind to what is outside it. If I "know" a thing, I have the thing, the thing that is not me, in my mind. But if there is only simply God, how does he "have" himself in his mind?
An interesting question worth thinking about.
I grant that God cannot create himself. For if he creates himself then he causes himself to exist, and nothing can cause itself to exist. For a thing cannot enter into a causal relation unless it exists. So if God causes himself to exist, then his existence is logically, if not temporally, prior to his existence. And that, we agree, is impossible.
The main point is that the existence of a thing cannot be logically prior to its existence. (And if it cannot be logically prior, then it cannot be temporally prior either.) But the existence of a knower not only can but must be logically prior to its self-knowledge. I cannot know myself unless I exist, but I can exist without knowing myself. In the finite case, then, it is clear that existence is logically prior to self-knowledge, and indeed other-knowledge as well.
Now God is omniscient and exists in all possible worlds. So there is no possible situation in which he does not know himself or fails to know everything there is to know about himself. If we think of God as omnitemporal as opposed to eternal, then at every moment he enjoys full self-knowledge. At every moment, his existence and self-knowledge are simultaneous. But this is not a problem since there is no problem with God's existence being logically prior to his self-knowledge even if the former is not temporally prior to the latter. We get the same result if God is eternal.
In sum, God's existence cannot be logically prior to God's existence as it would have to be if God creates himself. But God's existence can be logically prior to God's self-knowledge.
There is a second problem that the reader conflates with one I just discussed. If God alone exists, how can God know himself if "Knowledge is a relation in the mind to what is outside it"? This problem is solved by denying the assumption. Self-knowledge is NOT a relation to what is outside the mind. I feel good right now, and I know it. The object of my knowledge is an internal state. God's self-knowledge can be said to be analogous to finite self-knowledge.
If God simply is his act of existence, and if his existence is necessary, how can God have knowledge of contingent truths? What I mean is that it is possible for God to do other than he does (say not create, or create different things.) If he did differently – say, if the world didn't exist – his knowledge would be different in content. Yet God is supposed to be a single act of being, purely simple and identical across all possible worlds. God's essence just is his act of necessary existence, knowing and willing. It seems God's knowledge of contingents thus is an accident in him. But God can have no accidents. How then can he, as actus purus and necessary existence, have properties (such as knowing x or willing x) which he may not have had ?
That is a clear statement of the difficulty. As I see it, the problem is essentially one of solving the following aporetic tetrad:
1) God is simple: there is nothing intrinsic to God that is distinct from God.
2) God knows some contingent truths.
3) Necessarily, if God knows some truth t, then (i) there an item intrinsic to God such as a mental act or a belief state (ii) whereby God knows t.
4) God exists necessarily.
The classical theist, Aquinas for example, is surely committed to (1), (2), and (4). The third limb of the tetrad, however, is extremely plausible. And yet the four propositions are collectively inconsistent: they cannot all be true.
For example, it is contingently true that Socrates published nothing and contingently true that God knows this truth. He presumably knows it in virtue of being in some internal mental state such as a belief state or some state analogous to it. But this state, while contingent, is intrinsic to God. The divine simplicity, however, requires that there be nothing intrinsic to God that is distinct from God. Since God exists necessarily, as per (4), the belief state exists necessarily, which contradicts the fact that it must exist contingently.
That philosophers disagree is a fact about which there is little disagreement, even among philosophers. But what this widespread and deep disagreement signifies is a topic of major disagreement. One issue is whether or not the fact of disagreement supplies a good reason to doubt the possibility of philosophical knowledge.
The contemporary Czech philosopher Jiří Fuchs begins his book Illusions of Sceptics(2016) by considering this question. He grants that the "cognitive potential of philosophy" is called into question by the "embarrassing fact that there is not a single thing that philosophers would agree on." (13) Nevertheless, Fuchs insists that we have no good reason to be skeptical about the possibility of philosophical knowledge. His view is that "Discord among philosophers can . . . be sufficiently explained by the frequent prejudices of philosophers . . . Consequently, the existence of discord among philosophers does not imply that their work is of fundamentally unscientific character." (16)
Besides the prejudices of philosophers, the lack of consensus among philosophers may also be attributed to philosophy's difficulty: "the discord may just be a consequence of the specific challenging character of philosophy."(19)
Fuchs maintains that "consensus has no relation to the core of scientific quality. . . ." (24). The core of scientific quality is constituted by "proof or demonstration." (24) His claim is that interminable and widespread disagreement or lack of consensus has no tendency to show that philosophy is incapable of achieving genuine knowledge, where such knowledge involves apodictic insight into the truth of some philosophical propositions.
There are two main issues we need to discuss. One concerns the relation of consensus and truth; the other the relation of consensus and knowledge. My impression is that Fuchs conflates the two issues. I will argue, contra Fuchs, that while it is obvious that consensus and truth are logically independent, logical independence is not obvious, and is arguably absent, in the case of consensus and knowledge. My view, tentatively held, is that the lack of consensus in philosophy does tend to undermine philosophy's claim to be knowledge.
Consensus and Truth
I maintain, and Fuchs will agree, that the following propositions are true if not platitudinous.
1) Truth does not entail consensus. If a proposition is true, it is true whether or not there is consensus with respect to its truth.
2) Consensus does not entail truth. If most or all experts agree that p, it does not follow that p is true.
3) Consensus and truth are logically independent. This follows from (1) in conjunction with (2). One can have truth without consensus and consensus without truth.
Lack of consensus, therefore, does not demonstrate lack of truth. Even if no philosophical proposition wins the agreement of a majority of competent practitioners, it is possible that some such propositions are true. But it doesn't follow that some philosophical propositions have 'scientific quality.' To have this quality they have to be true, but they also have to be knowable by us. But what is knowability and how does it relate to consensus? To answer this question we must first clarify some other notions.
Truth, Knowledge, Knowability, Cognitivity, Justification, and Certainty
I add to our growing list the following propositions, perhaps not all platitudinous and not all agreeable to Fuchs:
4) Knowledge entails truth. If S knows that p, it follows that p is true. There is no false knowledge. There are false beliefs, and indeed false justified beliefs; but there is no false knowledge. You could think of this as an analytic/conceptual truth, or as a truth about the essence of knowledge.
5) Truth does not entail knowledge. If p is true, it does not follow that someone (some finite mind or ectypal intellect) knows that p.
6) Truth does not entail knowability by us. If, for any proposition p, p is true, it does not follow that there is any finite subject S such that S has the power to know p. There may be truths which, though knowable 'in principle,' or knowable by the archetypal intellect, are not knowable by us.
7) Cognitivity does not entail knowability. Let us say that a proposition is cognitive just in case it has a truth value. Assuming bivalence, a proposition is cognitive if and only if it is either true, or if not true, then false. Clearly, cognitivity is insufficient for knowability. For if a proposition is false, then it is cognitive but cannot be known because it is false. And if a proposition is true, then it is cognitive but may not be knowable because beyond our ken.
8) Knowledge entails justification. If S believes that p, and p is true, it does not follow that S knows that p. For knowledge, justification is also required. This is a bit of epistemological boilerplate that dates back to Plato's Theaetetus.
9) Knowledge entails objective certainty. Knowledge implies the sure possession of the object of knowledge; if the subject is uncertain, then the subject does not have knowledge strictly speaking.
Consensus and Knowledge
Fuchs and I will agree that consensus is not necessary for truth: a true proposition need not be one that enjoys the consensus of experts. But consensus may well be necessary for knowledge. Fuchs, however, seems to conflate truth and certainty, and thus truth with knowledge. A truth can be true without being known by us; indeed, without even being knowable by us. But, necessarily, whatever is known is true. On p. 30 we read:
By denying that the thought processes of philosophers can exhibit a scientific quality simply because of the existence of discord among philosophers, we make consensus a necessary condition for the general validity and potential certainty of scientific knowledge, which is the attribute of science. (Emphasis added.)
On the following page we find the same thought but with a replacement of 'potential certainty' by 'certainty':
. . . the necessary question of whether the consensus of experts is really such an essential and indispensable condition for the certainty and general validity of scientific knowledge. (31, emphasis added.)
When one speaks of the validity of a proposition, one means its truth. ('Valid' as a terminus technicus in formal logic is not in play here.) So it seems clear that Fuchs is maintaining that consensus is necessary neither for the truth of propositions nor for their certainty. He seems to be maintaining that one can have certain knowledge of a proposition even if the consensus of experts goes against one. This is not obvious. Why not?
Knowledge requires justification. Now suppose I accept the proposition that God exists and that my justification takes the form of various arguments for the existence of God. Those arguments will be faulted by an army of competent practitioners, not all of them atheists, on a variety of grounds. What's more, the members of the atheist divisions will marshal their own positive arguments, in first place arguments from evil. Now if just one of my theistic arguments is sound, then God exists. But I do not, by giving a sound argument for God, know that God exists unless I know that the argument I have given is sound. (A sound argument is a valid deductive argument all of the premises of which are true.) But how do I know that even one of my theistic arguments is sound? How can I legitimately claim to know that when a chorus of my epistemic peers rises up against me?
If what I maintain is true, then it is true no matter how many epistemic peers oppose me: they are just wrong! Truth is absolute: it is not sensitive to the vagaries of agreement and disagreement. Justification, however, is sensitive to agreement and disagreement. Or so it seems to me. My justification for considering a certain argument sound is undermined by your disagreement assuming that we are both competent in the subject matter of the argument and we are epistemic peers. You may disagree with what I just wrote, and thus disagree with me about the implications of disagreement, but you ought to grant that I am raising a very serious question here. (If you don't grant that, then you get the boot!)
In a situation in which my justification for believing that p is undermined by the disagreement of competent peers, there is no certainty that p. If knowledge logically requires certainty, and certainty is destroyed by the disagreement of competent peers, then I can no longer legitimately claim to know that p. So, while truth has nothing to fear from lack of agreement, knowledge does. For knowledge requires justification, and justification can be augmented or diminished by agreement or disagreement, respectively.
Interim Conclusion
Fuchs makes things too easy for himself by conflating truth and knowledge. We can agree that consensus is logically irrelevant to truth. Protracted disagreement by the best and the brightest over the truth value of p has no tendency to show either deductively or inductively that p is not either true or false. Truth is absolute and thus insulated from the vagaries of opinion. But truths (true propositions) do not do us any good unless we can know them. It is not enough to know that some truths are known; what we need is to know of a given truth that it is true. But disagreement inserts a skeptical blade between the truth and our knowledge of it.
Disagreement in philosophy undermines her claims to knowledge. As I see it, Fuchs has done nothing to undermine this undermining.
Suppose I become aware of something while dreaming. Does the fact that I am dreaming invalidate the content of my awareness? Or are there cases in which I become veridically aware that p even while and despite dreaming?
In bed I am puzzling over a chess problem. The book drops from my hands and I fall asleep. The solution occurs to me in a dream, and I later upon waking verify that it is correct. This happens. The solution I dreamt was correct despite my having dreamt it. So not everything that appears in a dream is invalidated by so appearing.
Or during a dream it occurs to me that the number of primes between 13 and 19 inclusive is itself prime. (A prime number is an integer greater than 1 the positive integer divisors of which are only 1 and the number itself. Examples: 2, 3, 5, 7, 11, 13, 17, 19, 23, and 29.) The content of my dream-thought is true, indeed necessarily true. So again one cannot validly infer the invalidity of a dream content from the fact that it is a dream content.
Are all items of a priori knowledge that are knowable while awake also knowable while dreaming? I think so. At least in principle. Suppose I come to know a priori by working through the proof that Zorn's Lemma is equivalent to the Axiom of Choice. Could I come to this insight while dreaming? In principle, yes, but not in practice inasmuch as I would need to have visual aids, paper, pencil, books, etc.
In sum, my dreaming that p is consistent with the truth of p if p is knowable a priori.
Due to my embodiment and its limitations, what I know a priori I know in most cases only on the occasion of sense experience, but never on the basis of sense experience. (That's what makes it a priori.) Now suppose there is a visio intellectualis, an intellectual intuition, not only of necessary truths, but also of spiritual substances. Suppose there is mystical knowledge of God or of Persons of the Triniity. Would such mystical insight, if veridical, lose one iota of its veridicality if it were enjoyed while dreaming? Why should it? Perhaps the quiescence of the senses and bodily functions in sleep disposes us toward such extraordinary experiences.
"You're speculating!" No doubt. But if a philosopher can't speculate, who can?
This entry continues yesterday's discussion. The question was: How can an ontologically simple God know contingent truths? Here again is yesterday's aporetic tetrad:
1. God is simple: there is nothing intrinsic to God that is distinct from God.
2. God knows some contingent truths.
3. Necessarily, if God knows some truth t, then (i) there an item intrinsic to God such as a mental act or a belief state (ii) whereby God knows t.
4. God exists necessarily.
I briefly discussed, without endorsing, an externalist way of rejecting (3). Reader Dan M. has a different idea for rejecting (3):
. . . a kind of nominalism about mental acts or states.
To illustrate, consider this truth: (A) Bill is sitting. Because 'Bill' is a singular term denoting a man, (A)'s truth implies the existence of at least one item. But there's disagreement about whether (A) implies the existence of other items. A property realist might say: (A) implies the existence of a property, sitting-ness. An event or state realist might say: (A) implies the existence of an event or state, Bill's sitting. But a nominalist may say: no, an item (e.g. Bill) can be a certain way (e.g. sitting), without that consisting in (or otherwise committing us to) the existence of any further items (such as a property of sitting, or a state or event of Bill's sitting).
Bringing in God's knowledge, we can say: (B) God knows that Bill has two cats. Someone who accepts proposition 3 might say: (B) implies the existence of an item intrinsic to God, namely a particular state of knowledge. If I understand you on knowledge externalism, that sort of response takes issue with 'intrinsic'. On the alternative view I'm entertaining, we take issue with 'item' instead. We say: there is no item of God's knowing that Bill has two cats. Just as Bill can sit without there being a state of Bill's sitting (construed as a bona fide item), God can know that something is the case without there being a state of God's knowing it (construed as a bona fide item).
Very interesting!
The suggestion, to put it generally, is that if a subject S believes/knows/wants/desires (etc.) that p, a correct ontological assay of the situation will not turn up anything in addition to S and p. Thus there is no need to posit any such item as the state (or state of affairs or fact or event) of S's believing/knowing/wanting/desiring that p. So on Dan's proposal, if 'God knows that Bill has two cats' is true, this truth does not commit us ontologically to the state (state of affairs, fact, event) of God's knowing that Bill has two cats.
In Cartesian terms, there is an ego and a cogitatum, but no cogitatio. This amounts to a denial of mental acts and thereby a denial of the act-content distinction.
Well, why not? One reason off the top of my head is that such a parsimonious scheme cannot account for the differences among believing, doubting, suspending judgment, wanting, desiring, willing, imagining, remembering, etc.
One and the same proposition, that Bill has two cats, is known by me, believed but not known by my loyal and trusting readers, doubted by a doubting Thomas or two, suspended by Seldom Seen Slim the Skeptic who takes no position on the weighty question of the extent of my feline involvement, remembered by last year's house guests, etc. Indeed, one and the same subject can take up different attitudes toward one and the same proposition.
Suppose a neighbor tells me there's a mountain lion in my backyard. I begin by doubting the proposition, suspecting my neighbor of confusing a mountain lion with a bobcat, but then, seeing the critter with my own eyes, I advance to believing and perhaps even to knowing. So one and the same subject can take up two or more different attitudes toward one and the same proposition.
These examples are phenomenological evidence that we cannot eke by with just the subject and the object/content but also need to posit mental acts, particular mental occurrences or episodes such as Bill's seeing here and now that there is a mountain lion in his backyard. The differences among believing, knowing, doubting, desiring, remembering, etc. will then be act-differences, differences in the types of mental acts.
How would a resolute denier of mental acts account for these differences? Will he shunt all the differences onto propositional contents? Will he theorize that there are memorial, imaginal, dubitable, desiderative, etc. propositional contents? Good luck with that.
Suppose that S goes from doubting that p to believing that p. The denier of mental acts would have to redescribe the situation as one in which there are two propositions, call them a dub-prop and a cred-prop, with awareness of the first followed by awareness of the second. How could one display these two propositions? Dubitably, there is a mountain lion on the backyard and Credibly, there is a mountain lion in the back yard?
Perhaps such a theory can be worked out plausibly. But it makes little sense to me.
And so we are brought back to our problem: How can a simple God know contingent truths?
I've been researching the doctrine of divine simplicity (DDS) recently and I've had a hard time figuring something out. On DDS, is it the case that God is identical with his thoughts? Surely on the view (as you say in your SEP article) God is identical with his omniscience. But does that also mean he is identical with the content of that attribute?
I would appreciate your input on this question, and your SEP article has given me a lot to think about.
The good news for Theophilus is that he has stumbled onto a serious problem. The bad news is that there is no really satisfactory solution known to me.
On DDS, God is identical to his attributes. Omniscience is one of the divine attributes; ergo God is identical to omniscience. This seems to imply that God is identical to the mental states in which his omniscience is articulated. But a good lot of what God knows is contingent, for example, that I am the author of the SEP entry in question. Someone else might have been the author of that encyclopedia entry, not to mention the fact that there might not have been any such entry, or any such encyclopedia.
If we think of knowledge as a propositional attitude, and if this holds for God as well as for us, then there are many contingently true propositions with respect to which God is in corresponding contingent mental states. For if it is contingent that p, then it is contingent that God is in the state of knowing that p. Thus God is contingently in the state — call it S — of knowing that there is such an on-line publication as the Stanford Encyclopedia of Philosophy.
But how can God be identical to S? This, I take it, is the question that vexes Theophilus. He is right to be vexed. How can an ontologically simple God know contingent truths?
The problem may be cast in the mold of an aporetic tetrad:
1. God is simple: there is nothing intrinsic to God that is distinct from God.
2. God knows some contingent truths.
3. Necessarily, if God knows some truth t, then (i) there an item intrinsic to God such as a mental act or a belief state (ii) whereby God knows t.
4. God exists necessarily.
The plausibility of (3) may be appreciated as follows. Whatever else knowledge is, it is plausibly regarded as a species of true belief. A belief is an intrinsic state of a subject. Moreover, beliefs are individuated by their contents: beliefs or believings with different contents are different beliefs or believings. It cannot be that one and the same act of believing has different contents at different times or in different possible worlds.
That the tetrad is inconsistent can be seen as follows. Suppose God, who knows everything there is to be known, knows some contingent truth t. He knows, for example, that I have two cats. It follows from (3) that there is some item intrinsic to God such as a belief state whereby God knows t. Given (1), this state, as intrinsic to God, is not distinct from God. Given (4), the state whereby God knows t exists necessarily. For, necessarily, if x = y, and x is a necessary being, then y is a necessary being. But then t is necessarily true. This contradicts (2) according to which t is contingent.
Opponents of the divine simplicity will turn the tetrad into an argument against (1). They will argue from the conjunction of (2) & (3) & (4) to the negation of (1). The classical theist, however, accepts (1), (2), and (4). If he is to solve the tetrad, he needs to find a way to reject (3). He needs to find a way to reject the idea that when a knower knows something, there is, intrinsic to the knower, some mediating item that is individuated by the object known.
So consider an externalist conception of knowledge. I see a cat and seeing it I know it — that it is and what it is. Now the cat is not in my head; but it could be in my mind on an externalist theory of mind. My awareness of the cat somehow 'bodily' includes the cat, the whole cat, all 25 lbs of him, fur, dander, and all. Knowledge is immediate, not mediated by sense data, representations, mental acts, occurrent believings, or any other sort of epistemic intermediary or deputy. Seeing a cat, I see the cat itself directly, not indirectly via some other items that I see directly such as an Husserlian noema, a Castanedan ontological guise, a Meinongian incomplete object, or any other sort of merely intentional object. On this sort of scheme, the mind is not a container, hence has no contents in the strict sense of this term. The mind is directly at the things themselves.
If this externalism is coherent, then then we can say of God's knowledge that it does not involve any intrinsic states of God that would be different were God to know different things than he does know. For example, God knows that I have two cats. That I have two cats is an actual, but contingent fact. If God's knowledge of this fact were mediated by an item intrinsic to God, a mental act say, an item individuated by its accusative, then given the divine simplicity, this item could not be distinct from God with the consequence that the act and its accusative would be necessary. This consequence is blocked if there is nothing intrinsic to God whereby he knows that I have two cats.
I don't find externalism plausible, so I am left with an impasse. I cannot see how God can exist without being ontologically simple. So I cannot reject (1). And of course I cannot solve or rather dissolve the problem by disposing of the presupposition that God exists. As for (2), I am not about to deny that there are contingent truths or that God knows contingent truths. As for (4), if God is simple, then surely he is a necessary being. A being that is its existence cannot not exist.
Few philosophers will follow me to the conclusion that our tetrad is a genuine aporia. Most theists will cheerfully deny (1). A few will deny (4) which implies the denial of (1). Atheists will dismiss the whole discussion as an empty academic exercise since it is plain to them that there is no God. A few brave souls will deny (2) either by denying that there are contingent truths or that God knows them. And then there are those who will deny (3). This I should think is the best way to go if there is a way forward.
Could we go mysterian on this? The limbs of the tetrad are each of them true, and so collectively consistent; it is just that we cannot understand how they could all be true.
REFERENCE: W. Matthews Grant, "Divine Simplicity, Contingent Truths, and Extrinsic Models of Divine Knowing," Faith and Philosophy, vol. 29, no. 3, July 2012, pp. 254-274.
A reader inquires, "I'm curious, if someone asked you what you were more certain of, your hands or belief in the existence of God, how would you respond?"
The first thing a philosopher does when asked a question is examine the question. (Would that ordinary folk, including TV pundits, would do likewise before launching into gaseous answers to ill-formed questions.) Now what exactly am I being asked? The question is ambiguous as between:
Q1. Are you more certain of the existence of your hand or of the existence of God?
Q2. Are you more certain of the existence of your hand or of your belief in the existence of God?
My reader probably intends (Q1). If (Q1) is the question, then the answer is that I am more certain of the existence of my hands than of the existence of God. My hands are given in sense perception throughout the day, every day. Here is one, and here is the other (he said with a sidelong glance in the direction of G. E. Moore). It is not perfectly certain that I have hands, or even that I have a body – can I prove that I am not a brain in a vat? — but it is practically certain, certain for all practical purposes.
By the way, it borders on a bad joke to think that one can prove the external world by waving one's hands around as Moore famously did. Still, if I don't know basic facts such as these 'handy' facts, then I know very little, things of the order of 'I now seem to see a hand' but not 'I now see a hand.' (I am using 'see' as a verb of success: If S sees an F, there there exists an x such that x is F and S sees x.)
So, for practical purposes, I am certain that my hands exist. But I am not certain in the same sense and to the same degree that God exists. The evidence is a lot slimmer. This is not to say that there is no evidence. There is plenty of evidence, it is just that it is not compelling. There is the evidence of conscience, of mystical and religious experience, the consensus gentium; there is the 'evidence' of the dozens and dozens of arguments for the existence of God, there is the testimony of prophets. But none of this evidence, even taking the whole lot of it together, gets the length of the evidence of my hands that I get from seeing them, touching them, clapping them, manipulating things with them.
When I fall down and feel my hands slam into the hard hot rock of a desert canyon, then I know beyond any practical doubt that hands exist and rock exists. Then I say with 'Cactus Ed' Abbey, "I believe in rock and sun." In that vulnerable moment, alone in a desolate desert canyon, it is very easy to doubt that there is any providential order, that there is any ultimate intelligibility, that there is any Sense beyond the flimsy and fragmented sense we make of things. But it is practically impossible to doubt hands and rock and sun.
The difference could be put like this. The existence and the nonexistence of God are both of them epistemic possibilities: for all I can claim to know, there is no God; but also: there is a God. Both states of affairs are consistent with what I can claim to know. But it is not an epistemic possibility that these hands of mine do not exist unless one takes knowledge to require an objective certainty impervious to hyperbolic doubt.
In the case of my hands there is really no counter evidence to their existence apart from Cartesian hyperbolic doubt. But in the case of God, not only is the evidence spotty and inconclusive, but there is also counter evidence, the main piece of which is the existence of evil. It is worth noting, however, that if one would be skeptical, one ought to doubt also the existence of evil, and with it, arguments to the nonexistence of God from the putative fact of evil. How do you know there is evil? No doubt there is pain, excruciating pain. But is pain evil? Maybe pain is just a sensation that an organism feeling it doesn't like, and the organism's not liking it is just an attitude of that organism, so that in reality there is no good or evil. Pain is given. But is evil given? Pain is undeniable. But one can easily deny the existence of evil. Perhaps the all is just a totality of value-indifferent facts.
As for (Q2), it makes reference to my belief in God. Whether you take the belief as a disposition or as an occurrent state, the belief as a feature of my mental life must be distinguished from its truth-value. I am not certain of the truth of my belief that God exists, but I am certain of the existence of my belief (my believing) that God exists. As certain as I am that I have hands? More certain. I can doubt that I have hands in the usual Cartesian way. But how can I doubt that fact that I have a belief if in fact I have it?
How ubiquitous, yet how strange, is sameness! A structure of reality so pervasive and fundamental that a world that did not exhibit it would be inconceivable.
How do I know that the tree I now see in my backyard is numerically the same as the one I saw there yesterday? Alvin Plantinga (Warrant and Proper Function, Oxford 1993, p. 124) says in a Reidian vein that one knows this "by induction." I take him to mean that the tree I now see resembles very closely the one I saw yesterday in the same place and that I therefore inductively infer that they are numerically the same. Thus the resemblance in respect of a very large number of properties provides overwhelming evidence of their identity.
But this answer seems open to objection. First of all, there is something instantaneous and immediate about my judgment of identity in a case like this: I don't compare the tree-perceived-yesterday, or my memory of the tree-perceived-yesterday, with the tree-perceived-today, property for property, to see how close they resemble in order to hazard the inference that they are identical. There is no 'hazarding' at all. Phenomenologically, there is no comparison and no inference. I just see that they are the same. But this 'seeing' is of course not with the eyes. For sameness is not an empirically detectable property or relation. I am just immediately aware — not mediately via inference — that they are the same. Greenness is empirically detectable, but sameness is not.
What is the nature of this awareness given that we do not come to it by inductive inference? And what exactly is the object of the awareness, identity itself?
A problem with Plantinga's answer is that it allows the possibility that the two objects are not strictly and numerically the same, but are merely exact duplicates or indiscernible twins. But I want to discuss this in terms of the problem of how we perceive or know or become aware of change. Change is linked to identity since for a thing to change is for one and the same thing to change.
Let's consider alterational (as opposed to existential) change. A thing alters iff it has incompatible properties at different times. Do we perceive alteration with the outer senses? A banana on my counter on Monday is yellow with a little green. On Wednesday the green is gone and the banana is wholly yellow. On Friday, a little brown is included in the color mix. We want to say that the banana, one and the same banana, has objectively changed in respect of color.
But what justifies our saying this? Do we literally see, see with the eyes, that the banana has changed in color? That literal seeing would seem to require that I literally see that it is the same thing that has altered property-wise over the time period. But how do I know that it is numerically the same banana present on Monday, Wednesday, and Friday? How do I know that someone hasn't arranged things so that there are three different bananas, indiscernible except for color, that I perceive on the three different days? On that extraordinary arrangement I could not be said to be perceiving alterational change. To perceive alterational change one must perceive identity over time. For there is change only if one and the same thing has different properties at different times. But I do not perceive the identity over time of the banana.
I perceive a banana on Monday and a banana on Wednesday; but I do not visually perceive that these are numerically the same banana. For it is consistent with what I perceive that there be two very similar bananas, call them the Monday banana and the Wednesday banana. I cannot tell from sense perception alone whether I am confronting numerically the same banana on two different occasions or two numerically different bananas on the two occasions. If you disagree with this, tell me what sameness looks like. Tell me how to empirically detect the property or relation of numerical sameness. Tell me what I have to look for.
Suppose I get wired up on methamphetamines and stare at the banana the whole week long. That still would not amount to the perception of alterational change. For it is consistent with what I sense-perceive that there be a series of momentary bananas coming in and out of existence so fast that I cannot tell that this is happening. (Think of what goes on when you go to the movies.) To perceive change, I must perceive diachronic identity, identity over time. I do not perceive the latter; so I do not perceive change. I don't know sameness by sense perception, and pace Plantinga I don't know it by induction. For no matter how close the resemblance between two objects, that is consistent with their being numerically distinct. And note that my judgment that the X I now perceive is the same as the X I perceived in the past has nothing tentative or shaky about it. I judge immediately and with assurance that it is the same tree, the same banana, the same car, the same woman. What then is the basis of this judgment? How do I know that this tree is the same as the one I saw in this spot yesterday? Or in the case of a moving object, how do I know that this girl who I now see on the street is the same as the one I saw a moment ago in the coffee house? Surely I don't know this by induction.
In response to two recent posts, here and here, Jacques comments:
I'm mostly persuaded by your recent posts about theism and knowledge, but I disagree about your claim that
"Presumably God can prove the existence of God, if he exists, not that he needs to."
Think of your condition 5 ["It is such that all its premises are known to be true."] if you can prove that p then you can derive p from an argument with premises all of which are known to be true. Suppose that God has some argument A for the conclusion that God exists. As you point out, A will either depend on premises taken to be self-evident, or an appeal to the seeming self-evidence of further premises in sub-arguments for the premises in A that are not taken to be self-evident. But now suppose that there's some premise P such that A is a proof of theism for God only if God takes P to be self-evident and P really is self-evident — in other words, only if P is 'objectively' self-evident and not just 'subjectively'. Of course, P might well appear to God to be self-evident; it might even appear to him that the objective self-evidence of P is itself objectively self-evident, and so on ad infinitum. But how could He really know, or be rationally entitled to believe, that P really is self-evident in the relevant sense rather than just seeming that way to Him? Sure, if He already knows that God exists, and that He Himself = God, then He can infer that the fact that P seems to him self-evident entails its real objective self-evidence. But how can He know that unless He can prove that He = God?
BV: The question seems to come down to whether or not the distinction between subjective and objective self-evidence applies to God as well as to us. It does apply to us. But I don't see that it applies to God. God's is an archetypal intellect, which implies that divine knowledge is creative of its object, whereas our knowledge is clearly not. If God knows that p by making it the case that p, then there is no logical gap between subjective and objective self-evidence for God.
On the other hand, it could be that God isn't even capable of proving anything. Maybe proofs are only possible for ignorant thinkers (who don't know directly, by acquaintance all the facts). But if He could prove or try to prove things I suspect His situation would be no better than ours with respect to His existence. Of course that conflicts with the (definitional?) fact of His omniscience, but maybe the conclusion should just be that the traditional concept of the Omni- God is incoherent.
BV: The divine intellect is intuitive, not discursive. God knows directly, not mediately via inferential processes. To know something in the latter way is an inferior way of knowing, and as such inappropriate to the divine intellect. Does it follow that God can't prove anything? I would hesitate to say that given the divine omnipotence: if he wanted to construct a proof he could. The point is that he doesn't need to. But we do need to employ inferential process to articulate and amplify our knowledge both deductively and inductively.
The main question, however, was whether WE can prove the existence of God. My answer to that is in the negative. The reason is due to the nature of proof as set forth in my definition. But perhaps you have a better definition.
To theists, I say: go on being theists. You are better off being a theist than not being one. Your position is rationally defensible and the alternatives are rationally rejectable. But don't fancy that you can prove the existence of God or the opposite. In the end you must decide how you will live and what you will believe.
About "Don't fancy that you can prove the existence of God or the opposite," Owen Anderson asks:
How would we know if that claim is itself true? Isn't it is possible that one or the other can indeed be proven?
To formulate my point in the declarative rather than the exhortative mood:
P. Neither the existence nor the nonexistence of God is provable.
How do I know (P) to be true? By reflection on the nature of proof. An argument is a proof if and only if it satisfies all of the following six requirements: it is deductive; valid in point of logical form; free of such informal fallacies as petitio principii; possesses a conclusion that is relevant to the premises; has premises each of which is true; has premises each of which is known to be true.
I say that an argument is a proof if and only it is rationally compelling, or rationally coercive. But an argument needn't be rationally compelling to be a more or less 'good argument,' one that renders its conclusion more or less rationally acceptable.
Now if my definition above gives what we ought to mean by 'proof,' then it is clear that neither the existence nor the nonexistence of God can be proven. Suppose you present a theistic or anti-theistic argument that satisfies the first five requirements. I will then ask how you know that the premises are true. Suppose one of your premises is that change is the conversion of potency into act. That is a plausible thing to maintain, but how do you know that it is true? How do you know that the general-ontological framework within which the proposition acquires its very sense, namely, Aristotelian metaphysics, is tenable? After all, there are alternative ways of understanding change. That there is change is a datum, a Moorean fact, but it would be an obvious mistake to confuse this datum with some theory about it, even if the theory is true. Suppose the theory is true. This still leaves us with the question of how we know it is. Besides, the notions of potency and act, substance and accident, form and matter, and all the rest of the Aristotelian conceptuality are murky and open to question. (For example, the notion of prime matter is a necessary ingredient in an Aristotelian understanding of substantial change, but the notion of materia prima is either incoherent or else not provably coherent.)
To take a second example, suppose I give a cosmological argument the starting point of which is the seemingly innocuous proposition that there are are contingent beings, and go on to argument that this starting point together with some auxiliary premises, entails the existence of God. How do I know that existnece can be predicated of concrete individuals? Great philosophers have denied it. Frege and Russell fanmously held that existence vannot be meaningfully predicated of individuals but only of cncepts and propositional functions. I have rather less famoulsy argued that the 'GFressellina' view' is mstaken, but this is a point of controversy. Furtrhertmore, if existence cannot be meaningfully predicated of individuals, how can individuals be said to exist contingently?
The Appeal to Further Arguments
If you tell me that the premises of your favorite argument can be known to be true on the basis of further arguments that take those premises as their conclusions, then I simply iterate my critical procedure: I run the first five tests above and if your arguments pass those, then I ask how you know that their premises are true. If you appeal to still further arguments, then you embark upon a vicious infinite regress.
The Appeal to Self-Evidence
If you tell me that the premises of your argument are self-evident, then I will point out that your and my subjective self-evidence is unavailing. It is self-evident to me that capital punishment is precisely what justice demands in certain cases. I'll die in the ditch for that one, and pronounce you morally obtuse to boot for not seeing it. But there are some who are intelligent, well-meaning, and sophisticated to whom this is not self-evident. They will charge with with moral obtuseness. Examples are easily multiplied. What is needed is objective, discussion-stopping, self-evidence. But then, how, in a given case, do you know that your evidence is indeed objective? All you can go on is how things seem to you. If it seems to you that it is is objectively the case that p, that boils down to: it seems to you that, etc., in which case your self-evidence is again merely subjective.
The Appeal to Authority
You may attempt to support the premises of your argument by an appeal to authority. Now many such appeals are justified. We rightly appeal to the authority of gunsmiths, orthopaedic surgeons, actuaries and other experts all the time, and quite sensibly. But such appeals are useless when it comes to PROOF. How do you know that your putative authority really is one, and even if he is, how do you know that he is eight in the present case? How do you know he is not lying to you well he tells you you need a new sere in your semi-auto pistol?
The Appeal to Revelation
This is the ultimate appeal to authority. Necessarily, if God reveals that p, then p! Again, useless for purposes of proof. See Josiah Royce and the Paradox of Revelation.
Move in a Circle?
If your argument falls afoul of petitio principii, that condemns it, and the diameter of the circle doesn't matter. A circle is a circle no matter its diameter.
Am I Setting the Bar Too High?
It seems to me I am setting it exactly where it belongs. After all we are talking about PROOF here and surely only arguments that generate knowledge count as proofs. But if an argument is to generate a known proposition, then its premises must be known, and not merely believed, or believed on good evidence, or assumed, etc.
"But aren't you assuming that knowledge entails certainty, or (if this is different) impossibility of mistake?" Yes I am assuming that. Argument here.
Can I Consistently Claim to Know that (P) is true?
Owen Anderson asked me how I know that (P) is true. I said I know it by reflection on the concept of proof. But that was too quick. Obviously I cannot consistently claim to know that (P) if knowledge entails certainty. For how do I know that my definition captures the essence of proof? How do I know that there is an essence of proof, or any essence of anything? What I want to say, of course, is that it is very reasonable to define 'proof' as I define it — absent some better definition — and that if one does so define it then it is clear that there are very few proofs, and, in particular, that there are no proofs of God or of the opposite.
"But then isn't it is possible that one or the other can indeed be proven?"
Yes, if one operates with a different, less rigorous, definition of 'proof.' But in philosophy we have and maintain high standards. So I say proof is PROOF (a tautological form of words that expresses a non-tautological proposition) and that we shouldn't use the word to refer to arguments that merely render their conclusions rationally acceptable.
Note also that if we retreat from the rationally compelling to the rationally acceptable, then both theism and atheism are rationally acceptable. I suspect that what Owen wants is a knock-down argument for the existence of God. But if that is what he wants, then he wants a proof in my sense of the world. If I am right, that is something very unreasonable to expect.
There is no getting around the need for a decision. In the end, after all the considerations pro et contra, you must decide what you will believe and how you will live.
Life is a venture and an adventure. You cannot live without risk. This is true not only in the material sphere, but also in the realm of ideas.
Patrick Grim gives something like the following argument. What I know when I know that
1. I am making a mess
is an indexical fact that no one else can know. At most, what someone else can know is that
2. BV is making a mess
or perhaps, pointing to BV, that
3. He is making a mess.
Just as no one except BV can refer to BV by tokening the first-person singular pronoun, no one except BV has access to the indexical fact that, as BV would put it to himself, I am BV. Only BV is privy to this fact; only BV knows himself in the first-person way. Now an omniscient being knows everything that can be known. But although I am not omniscient, there is at least one proposition that I know — namely (1) — that is not known by any other knower, including an omniscient knower. So an omnisicent being is impossible: by its very definition it must know every fact that can be known, but there are indexical facts that it cannot know. God can know that BV is making a mess but he cannot know what I know when I know that I am making a mess. For any subject S distinct from God, the first-person facts appertinent to S are inaccessible to every mind distinct from S, including God's mind. That is what I take to be Grim's argument.
I suppose one could counter the argument by denying that there are indexical facts. But since I hold that there are both indexical propositions and indexical facts, that response route is not available to me. Let me see if I can respond by making a distinction between two senses of 'omniscience.'
A. X is omniscient1=df X knows every fact knowable by some subject or other.
B. X is omniscient[2] =df X knows every fact knowable by some one subject.
What indexical facts show is that no being is or can be omniscient in the first sense. No being knows every indexical and non-indexical fact. But a failure to know what cannot be known does not count against a being's being omniscient in a defensible sense of this term any more than a failure to do what cannot be done counts against a being's being omnipotent. A defensible sense of 'omniscience' is supplied by (B). In this second sense, God is omniscient: he knows every fact that one subject can know, namely, every non-indexical fact, plus all facts pertaining to the divine subjectivity. What more could one want?
Since no being could possibly satisfy (A), (A) is not the appropriate sense of 'omniscience.' Compare omnipotence. An omnipotent being cannot be one who can do just anything, since there are both logical and non-logical limits on what any agent can do. So from the fact that it is impossible for God to know what is impossible for any one being to know, it does not follow that God is not omniscient.
To sum up. There are irreducible first-personal facts that show that no being can be omniscient in the (A)-sense: Patrick Grim's argument is sound. But the existence of irreducible first-personal facts is consistent with the truth of standard theism since the latter is committed only to a being omniscient in the (B)-sense of 'omniscience.'
