Concept

Foreknowledge vs Causation

Intro

Here is one of the oldest knots in Christian thought. "If God already knows everything I am going to do, then I cannot really choose otherwise, can I? His foreknowledge locks it in. So free will is an illusion, and God might as well have caused my actions himself."

The knot dissolves the moment you separate two very different things.

Knowing something is going to happen is not the same as making it happen. A rooster crows before the sunrise. The rooster does not cause the sunrise; the rooster just happens to know the timing. Your friend who knows you well predicts what you will order at the restaurant before you order it. Her knowing does not steer your hand to the menu; you steer your hand, and she happens to know what you are going to choose. Confusing the two is so common that logicians have a name for it, post hoc ergo propter hoc, "after this, therefore because of this." It is a fallacy.

Apply the same distinction to God. God knowing today what you will do tomorrow is an epistemic relation, his mind tracking reality. Tomorrow's choice is still genuinely yours. His knowing it ahead of time no more makes him the cause of it than the rooster's crow causes the sun to rise. The order in time runs God-knows then you-choose, but the order of explanation runs you-choose then God-knows-because-of-that.

This is the central move that lets Arminian, Molinist, and most classical Christian thinkers hold to both real foreknowledge and real human freedom at once. Calvinists push back: if God's foreknowledge is rock-solid, the future is rock-solid, and rock-solid futures cannot be chosen otherwise. Open theists go the other direction and deny that God can foreknow free choices at all (the future is open, even to him). The page below walks each of the major Christian solutions: Boethius's eternal now (God sees all of time at once, not in sequence), Aquinas's timeless cognition, Molina's middle knowledge, and the Open-Theist denial.

The reason the question matters is that it sits under almost every debate about salvation, prayer, providence, and evil. Get the foreknowledge-vs-causation distinction wrong, and you end up either with a God who forces every action (which makes him author of sin) or a God who knows nothing in advance (which thins his sovereignty). Get it right, and there is room for both his all-knowing mind and your real responsibility.

In full

The philosophical and theological distinction between God's knowing what will happen (an epistemic relation) and God's causing it to happen (a causal relation). The distinction is foundational to the Arminian, Molinist, and broadly libertarian Christian replies to the Calvinist argument that "if God knew, He must have determined." Conversely, the question of whether the distinction holds, and on what metaphysics of time and divine eternity, is the central pressure on Open Theism, which denies that future free choices can be foreknown without determining them. This entry distinguishes the relation, surveys the classical solutions (Boethian eternalism, Thomistic timeless cognition, Molinist middle knowledge, Open-Theist denial), and locates the dispute in Scripture and the post-hoc-ergo-propter-hoc fallacy structure.

Core distinction

Two relations a knower can stand in to a future event:

Epistemic: to know that p will occur. Knowledge tracks reality; the knowing is a response to what will be (or is timelessly), not a cause of it.
Causal: to bring about that p occurs. Causation makes reality; the causer is the source of the obtaining state of affairs.

To conflate these is to commit a version of the post hoc ergo propter hoc fallacy ("after this, therefore because of this"). Standard illustrations from ris3n's Free Will Cheat Sheet:

A rooster crows before sunrise; the rooster's crowing does not cause the sunrise.
An umbrella opens before rain; the umbrella did not cause the rain.
Knowing what you will eat tomorrow does not force you to eat it.
Predicting a game's outcome does not produce the outcome.

The libertarian / Arminian application: God's foreknowledge that S will freely do A does not entail that God causes S to do A. If S's choice is truly free, God's foreknowledge is consequent on S's choice (not in a temporal sense, but in a logical / explanatory one). The choice is the truth-maker for the proposition God knows.

The Calvinist counter

The standard Calvinist response is not to confuse knowing with causing, but to argue:

God's foreknowledge cannot be epistemically passive in the libertarian sense, because God is the creator of the world He foreknows. He does not learn the future from outside it; He knows it because He has decreed it (or weakly actualized it, in the Molinist version).
The libertarian distinction works for human knowers (a meteorologist's prediction does not cause the weather) but is strained for the divine knower whose knowledge is constitutive of creation.
If a future free choice has a determinate truth value now, then prior to the agent's choosing, something makes that proposition true, and that something is either God's decree (Calvinism), the agent's would-be free disposition (Molinism), or there is no determinate truth value (Open Theism).

So the Calvinist accepts the distinction in principle but denies that it does the work the libertarian wants: even granted that knowing isn't causing, the grounds of God's knowledge of contingent free choices remain to be explained, and the Calvinist's answer is the divine decree.

Classical solutions

Boethian eternalism (the eternal-now)

Boethius, De Consolatione Philosophiae V (c. 524 CE), gives the classical solution:

God is eternal, not merely everlasting. Eternity is "the simultaneously whole and perfect possession of unbounded life."
For the eternal God, there is no future; all of time is present to Him in one indivisible nunc stans (standing now).
God's "foreknowledge" is therefore not really fore-knowledge (knowledge in advance); it is vision, God sees the free creaturely choice as it occurs, in His eternal present, the way an observer on a hilltop sees travelers passing on a road below without causing their travel.
A free choice in time is not necessitated by God's eternal seeing of it, just as my seeing you read this sentence does not cause you to read it.

The Boethian solution is taken up by Anselm, Aquinas, and most of the medieval tradition; it remains a leading contemporary Christian solution (Eleonore Stump and Norman Kretzmann, "Eternity," 1981).

Thomistic timeless cognition

Aquinas (Summa Theologiae I, q. 14, a. 13): God knows future contingents because His knowledge is measured by eternity, and eternity comprehends all of time at once. God's knowledge is the cause of things only as He wills them, for free creaturely choices, His knowing follows His permitting and concurring with the creature's act, not His determining it. Aquinas distinguishes God's knowledge of approval (what He wills positively) from His knowledge of vision (what He simply sees).

Molinist middle knowledge

Molinism (Luis de Molina, 1588) provides a different account: God knows future free choices because He knows, in His middle knowledge (scientia media), what each possible libertarian-free creature would freely do in each possible circumstance. The truth-maker for these counterfactuals of creaturely freedom is the would-be agent's libertarian disposition, not God's decree. God then chooses which feasible world to actualize.

Open Theist denial

Open Theism (Pinnock, Boyd, Sanders, Hasker) denies the distinction can coherently be sustained. The argument: if a future free choice has a determinate truth value now, then either it is metaphysically settled (in which case it is not free in the libertarian sense) or its truth value is grounded in something prior (which collapses into determinism or Molinism's grounding problem). Therefore, the genuinely libertarian future is not yet determinate, and so not knowable in propositional terms even by God. God knows the possibilities and their probabilities exhaustively; He does not "foreknow" the actualities until they actualize.

Biblical foundation

The Bible repeatedly distinguishes God's knowing from His causing:

Foreknowledge of free human acts. Jesus foretells Peter's denial (Matt 26:34) and Judas's betrayal (John 13:21-27). The traditional reading: foreknown without coerced. The Free Will Cheat Sheet uses Peter's denial as its central illustration: Jesus' prediction did not cause Peter to deny; Peter freely chose to deny out of fear, and Jesus knew he would.
Foreknowledge of conditionals (CCFs). 1 Sam 23:10-13, God tells David what the men of Keilah would do; David flees, and the would-be event never occurs. Matt 11:21, what Tyre and Sidon would have done. The Molinist proof texts.
Foreknowledge alongside human guilt. Acts 2:23, Christ delivered "by the predetermined plan and foreknowledge of God"; yet his crucifiers acted with culpable, free wickedness ("you nailed Him to a cross by the hands of godless men"). Foreknown, ordained, and freely / culpably done.
God's knowledge as response to free choice. 1 Peter 1:2, believers chosen "according to the foreknowledge of God." Rom 8:29, "whom He foreknew, He also predestined." Read as: predestination follows foreknowledge of free response.

The Augustinian / Reformed counter-texts

Eph 1:11, God "works all things after the counsel of His will." Not just knowledge but causal sovereignty.
Rom 9:16, "it does not depend on the man who wills or runs, but on God who has mercy." Read as restricting saving causation to God's mercy alone.
Acts 4:27-28, what the actors at the cross did was "whatever Your hand and Your purpose predestined to take place." More than foreknown, determined.
Prov 16:9, Prov 21:1, the heart plans, but the Lord directs the steps; the king's heart is in the Lord's hand.
Dan 4:35, God does according to His will "in the host of heaven and among the inhabitants of earth."

The Reformed reading: these texts speak of more than mere foreknowledge, they speak of effectual divine determination that is not in tension with creaturely freedom (compatibilistically conceived).

Spread of positions (where the distinction stands)

Calvinism, accepts the distinction in principle but denies that it preserves libertarian freedom; God's foreknowledge of free choices is grounded in His decree, and creaturely freedom is compatibilist freedom-in-acting-on-one's-own-desires.
Arminianism, leans heavily on the distinction; God foreknows what creatures will freely do in the libertarian sense, without causing those choices. Often paired with the Boethian eternal-now to relieve the temporal pressure.
Molinism, accepts the distinction and provides a robust mechanism (middle knowledge) for how God knows libertarian-free counterfactuals without causing them.
Open Theism, denies the distinction can be coherently sustained for libertarian-free futures: knowledge of contingent free futures is impossible in principle because there is nothing yet to know.
Catholic tradition, combines Boethian eternalism with Thomistic (or, post-Molina, Molinist) accounts of how God knows free contingents.
Eastern Orthodoxy, emphasizes the Boethian eternal-now and synergism; God's foreknowledge does not constrain creaturely freedom.

Standard objections (steel-manned)

The grounding objection (Calvinist and Open-Theist, against Arminian and Molinist). Even if knowing isn't causing, something makes the foreknown proposition true. If it's the future free choice itself, that choice must already exist in some sense to ground the truth, but it doesn't yet exist. So either God's knowledge is grounded in His own decree (Calvinist) or there is no determinate truth to ground (Open Theist).
The fixity objection. If God infallibly knows now what S will do at t, then it is now true that S will do A at t; but if it is now true, S cannot do otherwise; so S is not free. Reply (Boethian / Molinist): the necessity is necessitas consequentiae (the necessity of the consequence, if God knows X, then X) not necessitas consequentis (the necessity of the consequent, X is intrinsically necessary). S's choice remains contingent in itself, even though God's knowledge of it is infallible.
The Calvinist constructive objection. The libertarian / Arminian appeal to the foreknowledge-causation distinction is correct as far as it goes but does not yet address the positive texts of effectual determination (Acts 4:27-28, Eph 1:11), which speak not of mere foreknowledge but of decreeing.
The Open-Theist constructive objection (against Boethian eternalism). The eternal-now solution presupposes a B-theory of time (all moments equally real) that may not be biblically defensible; Scripture's narrative of God who responds, relents, and engages history fits more naturally with an A-theory and a temporal God.

Tensions

The relation between the metaphysics of time (A-theory vs. B-theory; presentism vs. eternalism) and the foreknowledge question is now widely recognized as load-bearing; positions on the one tend to drive positions on the other.
The grounding question is the philosophically sharpest: what makes the foreknown free choice true? The Calvinist, Molinist, and Open-Theist answers are mutually exclusive.
Pastorally, the distinction is often deployed (rightly or wrongly) to defuse the worry "if God knew, I had no choice"; the apologetic value is genuine but the metaphysics behind it is contested.