Christians often make the claim that God knows everything. If asked for specifics, they’ll say this includes knowledge about the future (foreknowledge) and that such knowledge is infallible. Christians also often make the claim that man has free will. Upon being asked for specifics, they’ll agree that free will entails the ability to freely make a choice. At quick glance, these claims may not appear to be in conflict. However, if we dig a little deeper into each of these claims, we’ll see that they are.

Let’s say Mark is faced with a free choice of A or B. He is due to make this choice on Tuesday (day 2). We’ll call Mark’s day 2 A/B choice variable Y. This means prior to day 2, variable Y has no value (or the choice lies in an unmade state), and on day 2, variable Y will acquire a value of either A or B – to be decided freely by Mark.

Given the Christian claim that God has infallible foreknowledge, this would mean God knows infallibly what A/B choice Mark will make when the choice still lies in an unmade state. To gain further clarity on this, it can be asked, “if it were asked on day 1 does God know infallibly what Mark’s day 2 A/B choice will be, would the answer be YES?”. Christians would typically agree.

So we’ll call God’s day 1 knowledge of Mark’s day 2 A/B choice variable X. If God knows infallibly on day 1 what Mark’s day 2 A/B choice will be, then it follows that X has a static or fixed value of either A or B as of day 1.

We now have three conditions:

1) X has a value of either A or B on day 1 and this value is fixed and cannot change. If it is A, it will remain A. If it is B, it will remain B. This follows the assertion that God has infallible knowledge of future events.

2) Y (or Mark’s day 2 A/B choice) receives its value on day 2. Once Y receives its value, it becomes locked. Prior to receiving its value, it could potentially become A or B, as Mark freely decides on A or B. This follows the assertion that Mark has free will or can freely make choices.

3) X is equal to Y. This follows the assertion that if it were asked on day 1 if God knows what Mark’s day 2 choice would be and the answer is YES.

Not all three of these conditions can be true.

If #1 & #2 are true, then #3 can’t be true, as X wouldn’t be equal to Y, nor would Y be equal to X. Not only would X receive a value at a different point in time than Y, but Y could be assigned a value in conflict with the static value of X.

If #1 & #3 are true, then #2 can’t be true. Mark wouldn’t be able to freely choose A or B, as variable Y would already be defined as being equal to variable X. Christians will often argue that Godknowledge of Mark’s future choice is a function of Mark’s day 2 choice. But this doesn’t hold true if the answer to the question “if asked on day 1, does God know what Mark’s day 2 A/B choice will be?” is YES.

If #2 & #3 are true, then #1 can’t be true. What this means is if variable Y gets its value on day 2, then variable X also gets its value on day 2 and gets the same value as variable Y. It then follows thatGod can’t have infallible knowledge on day 1 of Mark’s day 2 A/B choice.

Therefore, it is logically impossible for God (or anyone) to have infallible foreknowledge of a yet to be made free choice.



    • rongarret

      But God transcends time, space, and logic. So your argument does not apply to God 😉

      • InvisiblePinkUnicorn

        RG – If the argument doesn’t apply to God, then which of the following is true:

        1) X doesn’t have a static value as of day 1
        2) Y isn’t freely assigned a value by a human on day 2
        3) X is not equal to Y

        Before answering, please keep in mind the presuppositions.


    • donhbloomer

      If someone asks my granddaughter what her favorite color is, I know she will say “Pink!”
      Now, I do not have infallible foreknowledge. She could change her mind. But the main thing I wonder about is: what does it mater if an imaginary being supposedly knows everything or not? Would mater if some thought that god was definitely male and others thought that god was female? I do not see how any of this will help someone realize that supernatural beings do not exist.

    • wibble

      So why can’t God have nipped out to the future, seen what Mark freely chose, then come back to the present to register his ‘guess’? As long as god is magic, I don’t think this angle of attack gets you very far on the free will question. I wish I could help!

      • InvisiblePinkUnicorn

        Hi Wibble – Help me understand your thinking.

        If God went into the future and checked out Mark’s freely made choice, what impact would this have on when variable X and variable Y receive their values and how the value of variable Y is determined? Would variable X still have a static value as of day 1? Would variable Y still be freely chosen by a human on day 2?

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