The literature on will is organized around a small number of standing positions, each of which the framework engages directly. The engagement runs on three terms formally specified at [§8.9.2](<8.9.2 What is Required.md>) — the modal-mapping network (the structure that holds an agent's live alternatives), modal depth (how far that structure extends), and the modal field it presents — introduced here in their working sense. Each is taken up again by name at [§8.9.5](<8.9.5 What is Concluded.md>) once the structural account is in view.

*Libertarian free will.* The classical libertarian tradition (Chisholm 1964; van Inwagen 1983; Kane 1996; O'Connor 2000) holds that free will requires exemption from the causal structure of the natural world: a genuinely undetermined act, or an act produced by an agent acting as a first cause. The motivation is that if every act traces back to prior conditions the agent did not author, no act is properly the agent's own. The structural account presses where the position meets its own commitments. An agent acting outside any modal field acts on no possibilities, because possibility is the structure the field provides; an act with no modal context is not a free act but no act at all. Grant the libertarian the modal field, then, and press where freedom actually lives: in the *selection* among the live alternatives the field presents. That selection is either grounded in the agent's prior states — character, conviction, the modal map accumulated and installed in them — or it is not. If it is, the act issues from what the agent is, which is determination by the agent's own structure, not exemption from it; that is the structural account, not a rival to it. If it is not, then nothing about the agent explains why this outcome occurred rather than that one, and an unexplained selection is luck, not control — the very thing the libertarian invoked freedom to secure the agent against. The agent-causal refinement (Chisholm, O'Connor) — the agent *qua* substance as an irreducible first cause — appears to name a third thing, but the appearance depends on a self standing apart from its own structure, and [§7.8](<7.8 Life.md>) and [§8.5](<8.5 Identity.md>) have already foreclosed one: the agent just *is* the structured recursion, the self just *is* the self-model built within it. There is no substance over and above the modal-mapping network for an irreducible agent-cause to be. So the refinement collapses back into the fork: operate *through* the map and it is structure under another name; select with no basis in the map and the luck horn returns intact. The dilemma is general, and it is why the result is stronger than the mere actual absence of contra-causal freedom. Given the identification of the agent with a structured recursion ([§7.8](<7.8 Life.md>), [§8.5](<8.5 Identity.md>)), no contra-causal locus survives specification: pressed for its content, contra-causal freedom resolves into determination-by-structure or randomness, with no third thing available. The claim is modal, not merely actual — contra-causal freedom picks out no possible act — and it stands exactly as far as that identification does. The agent-causal theorist who would resist it must supply a self that is not its structure, which is the [§8.5](<8.5 Identity.md>) result over again. What libertarianism needed was depth within structure, which is what the modal-depth account supplies; the rejection of structure was the wrong move on a correct intuition.

*Hard determinism and hard incompatibilism.* The hard-determinist tradition (Pereboom 2001; Caruso 2012; Strawson 1994) holds that because every act is caused by prior conditions the agent did not author, no one is ever ultimately morally responsible for what they do. The structural account agrees that no agent authors itself from nothing and rejects the inference that responsibility therefore disappears. Responsibility tracks modal depth — the capacity to hold alternatives open, model consequences, inhibit response, and revise the field — not ultimate metaphysical sourcehood. Hard incompatibilism is correct that libertarian sourcehood is unavailable and incorrect that anything moral practice cares about depended on it.

*Classical compatibilism.* Compatibilist accounts from Hume forward (Hume 1748; Hobbes 1654; Frankfurt 1971; Watson 1975; Fischer and Ravizza 1998; Wolf 1990) hold that free will is compatible with determinism because what matters is the right kind of internal cause — desires endorsed by higher-order desires, reasons-responsive mechanisms, sanity-relative reasons-tracking. The structural account is the deepest version of this thought. The internal structure that does the work is a modal-mapping network: its depth supplies the alternatives a higher-order desire or a reasons-responsive mechanism would range over, while the agent's identification with one of the valuations the network holds is what those criteria were approximating. Compatibilism named the location; the structural account names what is there.

*Frankfurt cases and the principle of alternate possibilities.* Frankfurt (1969) argued by counterexample that responsibility does not require the ability to have done otherwise: an agent who acts on their own reasons, while unbeknownst to them a counterfactual intervener would have forced the same act had they tried to deviate, is still responsible despite lacking genuine alternatives. The literature has multiplied increasingly elaborate versions (Fischer 1994; Widerker and McKenna 2003; Pereboom 2001). The structural account dissolves the dispute by distinguishing what alternatives consist in. Frankfurt cases manipulate the external-world branching while leaving the agent's modal-mapping network — the inside of the act — intact. The freedom that matters is the depth of the internal map, not the count of metaphysically open branches. Responsibility therefore tracks modal depth even when external alternatives are foreclosed, exactly as Frankfurt argued, but on a structural reading rather than a counterexample-driven one.

*Hierarchical will and volitional necessity.* A second strand locates freedom not in how many alternatives lie open but in the agent's relation to their own desires. Frankfurt (1971) gives the hierarchical version: a wanton, moved by whichever first-order desire is strongest without caring which one moves them, is unfree with options to spare, while an agent is free when the desire that moves them is one they endorse by a higher-order desire. Watson (1975), routinely filed alongside Frankfurt but in fact the locus classicus critique of him, presses exactly the objection the hierarchy invites — a higher-order desire is only another desire, with no standing to confer authority, so ranking desires by order begins a regress rather than ending it — and substitutes a valuational reading: what makes a desire the agent's own is that it expresses what the agent values, the deliverance of a valuational system distinct from the mere strength of the motivational one. Bratman (2007) develops the same identificatory thought in terms of self-governing plans. The distinction is load-bearing here, because the endorsement criterion this chapter adopts is Watson's valuational one rather than Frankfurt's higher-order-desire one, and [§8.9.5](<8.9.5 What is Concluded.md>) answers Watson's regress worry rather than inheriting it. A later refinement (Frankfurt 1982, 1988) adds that the deepest form of such endorsement — volitional necessity, being unable to act against what one cares about most — is a height of freedom rather than a limit on it, and stands as the analytic tradition's most developed reply to the demand for open alternatives. The everyday failure of the same structure is the weakness of will tracked since Aristotle and sharpened by Davidson (1970): judging one course best and being carried into another. These positions press the modal-depth framing from a direction the alternatives-based disputes do not, since they turn on which valuation governs rather than on how many alternatives lie open; how depth and endorsement combine is taken up at [§8.9.5](<8.9.5 What is Concluded.md>).

*The Eden story.* The most developed classical reading of the Genesis narrative — present in Augustine and Aquinas, refined in the contemporary Catholic tradition — holds that Adam and Eve were created with perfectly oriented wills and full modal competence by divine endowment, so that the choice they faced was a free turning of an already-competent will rather than a choice that lacked the depth to count. The structural account presses where this reading meets its own commitments: a will competent to choose moral evil already requires a modal field rich enough to contain the alternative as live, and the field's structure is what the present account calls Nature; the endowment view relocates rather than removes the modal-depth requirement. And the endowment cuts against what the defender needs from it. A will acting on an *infused* map — competence conferred whole, as Aquinas's original justice and infused knowledge have it — is acting on modal-field content it did not author, so its selections are grounded in that installed structure: freedom in precisely the structural, modal-depth sense, not the contra-causal one. That modal content can be *installed* at all is no concession against this — education, language, and art install it piecemeal, divine infusion all at once, and in neither case does the will that acts on the map act independently of the map. Infusion therefore yields a structurally free will, not a contra-causally free one, and cannot rescue the libertarian reading of the first choice; the only question it leaves open is whether the infused map was *deep* enough for the choice to count as fully responsible — a question internal to the structural account, and one its account of accumulated, lived modal depth answers in the negative. On the structural reading — modal depth as accumulated terrain — the first humans are placed before a morally decisive choice before they have accumulated the modal depth required to understand it. They have no history of deception, no developed map of death, no prior moral failure, no experience of shame, alienation, guilt, punishment, or irreversible consequence. The act is formally voluntary, but formal voluntariness is not freedom. Freedom requires a modal network deep enough to understand what is being selected. On that standard, Eden is not the origin of fully responsible rebellion. It is the exposure of undeveloped will to a consequence it could not yet understand.

*Divine will.* The same analysis returns to divine will. The most developed classical reading — Aquinas's *actus purus* (pure actuality — being with no unrealized potential), refined in Stump (2003) and the contemporary Thomistic tradition — holds that divine willing is not the operation of selection across alternatives but a single, simple, eternal act in which what God wills and what God is are not distinct; on this view divine simplicity is preserved without surrendering the language of will, and the apparent absence of modal depth is not a defect but a higher-order feature of the divine mode of being. The structural account presses the dilemma the picture leaves intact. Classical God can be assigned modal status, but not modal depth. If God is pure actuality, there are no live alternatives, no delay, no unrealized possibilities, no selection, and no distance between willing and obtaining. That is not will; it is necessity wearing the grammar of will. If God has maximal modal depth instead, then God stands within a modal field rich enough to contain alternatives, contingencies, unrealized possibilities, and distinguishable possibilities. But to stand within such a field is to instantiate the structure God was supposed to transcend. The first option gives no will. The second gives Nature.

The standing positions in the philosophy of will divide along a single load-bearing axis: whether free will requires exemption from causal structure or admits some form of embedded freedom within it. [§8.9.2](<8.9.2 What is Required.md>) takes up the structural conditions any willing must meet, [§8.9.3](<8.9.3 What is Predicted.md>) the architecture those conditions predict, [§8.9.4](<8.9.4 What is Confirmed.md>) the empirical record, and [§8.9.5](<8.9.5 What is Concluded.md>) the disputed positions reframed.


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← [8.9 Will](<8.9 Will.md>) | [8.9.2 What is Required](<8.9.2 What is Required.md>) →
