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Omniscience Entails Fatalism

Captioned as "Odin disguised as a Travell...

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Dear friend in philosophy
Thank you for your recent charming company. As you might recall from our discussion at the restaurant, I remarked glibly that omniscience entails fatalism. You, of course, disagreed with me on the grounds that God’s existence is somehow atemporal. Since informal discussions over lunch, sadly cut short by your disappearance, are less than conducive to heavy philosophy, I thought this clarification in order.

I believe I can prove my assertion. Given a few reasonable assumptions, and a particular understanding of the concepts involved, we should be able to conclude logically from infallible omniscience that:

It’s impossible for Odin to know what you’ll do and for you to do otherwise.

This is what I mean when I say ‘omniscience entails fatalism.’ I take fatalism to mean ‘truth-values of propositions about future events are inalterable.’ Or, more simply, there are truths about the future and the future is therefore fixed by these truths. What is true about the future stays true.

Now, classically ‘omniscience‘ has been understood as ‘maximal and complete knowledge of all true propositions.’ I should note that I’m assuming infallible omniscience. That is, not only does Odin know everything but it’s impossible for Odin to believe a falsehood. I think this a plausible assumption – as does van Inwagen. However, if you’re unconvinced consider only the strangeness of an atemporal omniscient Odin, who could nevertheless possibly be mistaken.

Formal argument

Mouse-over the individual symbols to see what they mean. Click links to see the rules of inference used.

Informal argument

1. Necessarily, if Odin knows what you’ll do, then it’s true you’ll do it.
2. Necessarily, either Odin doesn’t know what you’ll do, or you’ll do it.
3. Necessarily, it’s not both the case that it’s false that Odin doesn’t know what you’ll do, and that you’ll do otherwise.
4. Necessarily, it’s false that Odin knows what you’ll do, and that you’ll do otherwise.
5. It’s impossible that it’s not false both that Odin knows what you’ll do and for you to do otherwise.

6. Therefore, it’s impossible that Odin knows what you’ll do and for you to do otherwise.

If you clicked on any of the Stanford Encyclopedia of Philosophy links, you’ll notice that my argument shares some commonalities with their argument. It is, however, entirely my own, and as far as I’m concerned it does more with less. Please note that I derived my conclusion from the single premise of infallible omniscience. Since the conclusion derives from a single premise, the premise and the conclusion are truth-functional equivalents. Saying that Odin infallibly knows what you’ll do, is – logically speaking – just a paraphrase of saying that it’s impossible for Odin to know what you’ll do and for you to do otherwise.

Truth Table

Truth TableSince the two sentences have the same truth-value under every truth-value assignment, they are truth-functionally equivalent.

Your objection

As for your objection from timelessness – i.e. Odin does not have foreknowledge because she is outside of time – I simply fail to see the relevance. Firstly, I’m not convinced that the act of knowing is coherent when applied to a “knower” outside time. Verbs imply change and change implies time. Perhaps you could have time without change, fine, but I can make nothing of  ‘change without time.’ Unless you’ll concede Odin as an entity without agency, or unless you’re ready to posit hyper-time, then Odin cannot be outside time.

Secondly, even if I concede this nonsense, I still don’t see how it applies. No particular temporal location of Odin is doing any work in this matter. What’s doing the work here is that there are true propositions about the future. We could run the same argument without any reference to either Odin or any other hypothetical future-knower. We all know that propositions can change truth-value, but, again, change implies time. There can be no atemporal change in truth-value unless you’re partial to presentism or hyper-time. In either case you shouldn’t also hold that there are propositional truths about future contingents.

Another common objection

The Objection From Cookie

A different objection I have encountered repeatedly – in private conversation and on the internet – is the assertion that just because Odin knows what you’ll do, she’s not forcing you to do it. Often objectors tout this by appeal to analogy. Suppose I have a son, the analogy goes, and place before him a plate of cookies before departing the room. I then know that my son will eat the cookies. However, I haven’t in any way forced him to do so and he’s choosing to eat the cookies of his own free will.

This is a silly objection for several reasons. The objector is guilty of equivocating more than once. Firstly, we’re now talking of knowledge in several degrees of certainty. Nobody claims parents have infallible omniscience about their children. The father’s knowledge doesn’t amount to an infallible certainty about the future proposition ‘my son will eat the cookies.’ The father’s knowledge is more of an educated guess. He doesn’t know infallibly that his son won’t drop dead before devouring any cookies, or that this isn’t the day his son finally grows a conscience. Odin, presumably, knows those things, so knows unconditionally what will happen. The father might be surprised, since he can’t account for everything. Odin has infallible knowledge of said everythings.

Secondly, we’re also juggling several ‘free will’ concepts. I dislike the term altogether and avoid using it when I can. My argument can certainly do without ‘free will,’ so there’s that. But to say a little more, it really depends on what you mean by ‘free will‘ and whether you’re consistent in your usage. If by ‘free will’ you mean ‘the ability to do otherwise than what Odin’s future-knowledge dictates,’ then you don’t have free will by my argument. If, however, you mean ‘the ability to act without coercion from anyone else,’ then sure, you do have ‘free will’ in light of my argument. Although I don’t see how it gets you anywhere closer to an objection.

The only solution


Either there'll be a seabattle or there won't

There is a solution to a consistent coexistence between Odin’s infallible omniscience and an open future. As far as I can see it’s the only solution. We can, like Aristotle, deny that propositions about the future have any truth-value. When the above-mentioned father says ‘my son is going to eat the cookies’ what he says is neither true nor false because it hasn’t happened yet. If there simply are no true propositions about the future, then Odin may have infallible knowledge about all true propositions unproblomatically while still allowing you to ‘do otherwise.’ Actually there isn’t an otherwise since there isn’t a wise for it to be other to – but you get my gist. Of course, this would still mean Odin doesn’t know the future. However, it wouldn’t detract from Odin’s omniscience any more than does Odin’s lack of knowledge about the distance in miles from Duckburg to Gotham City.

I trust I have clarified my side of our disagreement. Of course, I think you now ought to agree with me. However, that’s not likely to happen since I know we’re equals in stubbornness. Though you manage to pull it off far more gracefully than I. In any case take my explanation for what you will.

Your friend,

P.S. I have omitted mentioning my friend’s name for the sake of privacy. I shall leave it up to him/her whether to break anonymity.

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16 Responses to “Omniscience Entails Fatalism”

  1. Annoying Joe says:


    What about compatibilism?

    determinism that also has free will.

    In this scenario an appropriately knowledgeable scientist who can map your current states can tell what you’re going to do in the future – doesn’t mean its fatalistic.

    • Thank you for your comment.
      As I said in my post, my argument works fine without invoking ‘free will,’ whatever you mean by it.

      As far as I know compatibilism usually appeals to the ‘ability to act without coercion from any other person’ understanding of ‘free will’ and I already addressed that.

      As to a hypothetical scientist deriving future truths out of determinism, I would say that does entail fatalism as defined previously. However, if your point was that determinism alone doesn’t necessarily entail fatalism, I agree. (E.g. Cameron & Barnes – The Open Future)

  2. Annoying Joe says:

    [Please don’t “out” my friend – Heini]

  3. Diceman says:

    Heini took fatalism to mean ‘truth-values of propositions about future events are inalterable’ – is that the same definition you’re using? If the hypothetical scientist can tell you what you’ll do in the future with perfect accuracy then it doesn’t seem like the truth values they’ve found for propositions about future events are alterable.

  4. Arnfinn says:

    áhugavert at hugsa í hasun banum… men eg trúgvi ikki vit kunnu skilja hugtøk sum “outside time” og omniscience ordeliga.. og tá eg royni at gerða mær niðurstøgur, føli eg meg bara “sindur býttan” 🙂 akja.. onki verdur sum filosoff :p

    • Takk fyri viðmerkingina. Eg skilji ikki hví tú heldur at ongin kann skilja hugtøkini. Hvat grundar tú hettar á? Eg haldi meg ongan trupulleika hava við at skilja tey.

      • Arnfinn says:

        Jú eg trúgvi væl, at man kann halda seg skilja tað… men tað at man rennur seg í paradoksir og sovori allatíð, merkir fyri meg at vatni er alt for djúpt…. eitt paradoks kann ikki skiljast, men tað er til nevertheless… ella fari eg skeivur við at man ikki kann skilja eitt paradox ?

        • Eg haldi ein kann skilja eina tvørsøgn. Og tvørturímóti at fortelja okkum at “vatnið er ov djúpt,” so fortelur ein tvørsøgn okkum at vit hava gjørt ein feil onkrastaðni í okkara próvførslu. Ein tvørsøgn kann eisini fortelja okkum, at okkara deduktiva próvførsla er gildig, um vit fingu tvørsøgnina við at nokta niðurstøðuna og varðveita fortreytirnar. At skilja próvførslu krevur at ein skilur tvørsøgn.

          • Arnfinn says:

            blob blob blob… djúpt vatn :p er ik okkurt paradox til, hvar tú ikki kanst gerða tær nakra niðurstøðu ?

            • Kemur ann uppá hvat tú meinar. Men í fyrstu atløgu; nei.

              • Arnfinn says:

                vit skilja tað nokk ikki uppá sama máta so… eg meini ikki at man kann koma uttanum at tað eru pradoxir til í hugaheiminum, og eg meti at tað prógvar hvussu sera begrensa okkara vitan og hugflog er

                • Eg skilji ikki hvussu tú kemur til tí niðurstøðuna. Tvørsøgnir í hugaheiminum fortelja okkum at vit hava gjørt ein logiskan feil; at tað sum vit royna at siga er meiningsleyst. Tað merkir ikki at tað vit royna at siga passar, men at vit ikki skilja tað. Vit skilja netupp, at tað ikki passar.

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