Psychology · Philosophy · Executable knowledge

Acceptance, action,
and what follows

An executable reconstruction of Acceptance and Commitment Therapy in Axioma. Separate what a theory defines, what it assumes, what follows, and what evidence must still establish.

Working study · Version 0.2 · 6 September 2026
Axioma v0.9.0 development interpreter · Six independent examples · 25 executable checks

Press Run or /Ctrl+Enter. Each example starts with a fresh environment.interpreter: loading…
RESEARCH QUESTION

Does acceptance require inaction?

Each runnable example now pairs a source account with the formalization choices and the result it actually establishes. Modern sources are summarized in our words, with one brief quotation explicitly marked; the bibliography links to the consulted text. This applies the Handbook study’s source-to-model method without claiming that ACT and Stoicism are the same theory.

The apparent tension is productive: how can a theory emphasize accepting experience while also asking for behavioral change? ACT places psychological flexibility at the center of its model. It connects willingness to experience private events with action guided by values; acceptance is not presented as an end in itself. [1]

Our first question is therefore logical: does accepting an experience entail leaving a situation unchanged? We construct a small vocabulary in which the targets are explicit, inspect the resulting inferences, and test what happens when a premise is withdrawn. We also ask whether experiencing a thought establishes its content, and whether a treatment outcome establishes its proposed mechanism.

This is a study in knowledge representation and executable philosophy, not a treatment protocol or an efficacy review. Its contribution is an inspectable reconstruction of selected distinctions. A passing program establishes a result inside the stated model; it does not certify a psychological theory or provide a clinical assessment.

SOURCE MODEL

The vocabulary we inherit

The six processes below summarize the Association for Contextual Behavioral Science’s account. They are interrelated processes, not six independent switches or a diagnostic checklist. Psychological flexibility concerns contact with the present and persistence or change in behavior in the service of valued ends. [2]

ACT processes and their treatment in this first reconstruction
ProcessSource meaning, condensedWhat this study models
AcceptanceWilling contact with private events, without unnecessary attempts to control them.Willingness and chosen action are separate predicates.
Cognitive defusionChanging how thoughts function and how one relates to them.Thought occurrence is distinguished from proposition truth.
Contact with the presentAwareness of current psychological and environmental events.Only an explicit context argument; no model of attention.
Self-as-contextA perspective from which experiences can be noticed without attachment to their content.Described here; not operationalized in code.
ValuesChosen, continuing qualities of action, distinct from achievable goals.A continuing direction and a completed action use different relations.
Committed actionDeveloping effective patterns of behavior linked to chosen values.A finite, context-dependent candidate-action rule.

ACT’s philosophical setting is functional contextualism. The ACBS account evaluates behavior in context and identifies prediction and influence, with precision, scope and depth, as scientific aims. [3] For our model, this motivates a practical discipline: spell out the relevant person, situation, action and goal instead of attaching a universal “good” or “bad” label to an action.

That discipline is our formalization choice. A relation named serves does not independently establish what works, whose values should govern, or how to resolve conflicting values. Its input must come from an explicit assumption or an appropriate investigation. Relational Frame Theory is part of the theoretical background in the foundational ACT account; its learning mechanisms are outside this first model. [1]

01 · REPRESENTATION

A source claim is not yet a premise

We use four different statuses: a source report, a model definition, a stipulated case fact, and a defeasible explanatory hypothesis. A bibliographic label records where a statement came from. It does not automatically license the statement as true. In this example, the adoption step is deliberately visible.

The string flexibility_is_the_ACT_target abbreviates the theoretical aim described in the foundational account. [1] The predicates and the adoption rule are ours. The rule derives eligibility for our inference model, not the truth of ACT.

AXIOMA MODEL · OUR RECONSTRUCTION

Translation choices
reports records provenance; adopted explicitly enables available_for_inference.
Additional assumptions and scope
The provenance vocabulary and adoption rule are ours. A bibliographic report carries no automatic truth guarantee.
sources.axOpen in Playground ↗

Result: the source report exists before anything is adopted. After adoption, the premise still says postulate. Elsewhere, Axioma’s theorem label will mean strict derivation from supplied facts and rules, including hypothetical ones. Its conjecture label records defeasible derivation. Neither label is a confidence score. [4]

What running this establishes. A cited claim is available for inference only after the model’s adoption step.

02 · LOGICAL DISCIPLINE

What an extra implication would assume

ACT’s defusion vocabulary motivates separating an occurrence of thinking from the content of that thought. [2] We first examine the bare implication “a thought occurs, therefore its proposition is true.” A two-variable Boolean model has four assignments. An assignment with a true antecedent and a false consequent is a counterexample.

AXIOMA MODEL · OUR RECONSTRUCTION

Translation choices
Two independent Boolean propositions stand for occurrence and truth, or acceptance and absence of distress.
Additional assumptions and scope
These are finite logical assignments, not observations of patients. Their availability refutes an unconditional entailment under the selected vocabulary.
countermodels.axOpen in Playground ↗

Result: each proposed implication has one counterexample in this unconstrained Boolean space. The second reading separates acceptance from guaranteed symptom relief. This is a check of logical form, not a psychological experiment: we have supplied no empirical constraints that establish which assignments describe real people. Nor is it a finding that thoughts are generally false or that ACT cannot reduce symptoms. It identifies the additional premise a stronger claim would require.

What running this establishes. A thought can occur without its content being true; acceptance alone does not logically force absence of distress.

03 · CONDITIONAL CONSEQUENCE

Accept an experience; choose an action

Mira is a fictional student. For one seminar we stipulate willingness to experience anxiety and a choice to ask a question. Our rule merely defines the coexistence of these two facts in the same context. It does not claim that willingness causes the action, guarantees success, or makes the anxiety disappear.

AXIOMA MODEL · OUR RECONSTRUCTION

Translation choices
willing_to_experience and chooses_action keep the two targets explicit.
Additional assumptions and scope
Mira’s classroom case is invented. The coexistence rule is our definition, not a claim that willingness causes action.
acceptance_action.axOpen in Playground ↗

Result: coexistence is derived as a theorem, and its proof exposes both hypotheses. No symptom disappearance is derived. This supplies a witness to compatibility within the small model: accepting the experience and changing one’s participation do not contradict one another under these definitions. Calling this “resignation” would require an additional bridge from willingness to non-action; we have not inserted one.

An empty relation query means not derived in this knowledge base. It does not mean a negative fact has been established. That distinction matters especially when modeling incomplete psychological information.

What running this establishes. The selected premises are compatible. No symptom reduction is derived.

04 · CONTEXTUAL CHOICE

One direction, different next steps

The values–goals distinction motivates separating a continuing direction from a completed step. [1] We now supply an intentionally small policy: an action is a candidate when it serves the stipulated value in the current context and is feasible there. These conditions and the toy facts are our design, not an ACT decision algorithm.

AXIOMA MODEL · OUR RECONSTRUCTION

Translation choices
values, serves and feasible determine a finite set of candidate actions.
Additional assumptions and scope
The learner’s value, feasibility facts and service relation are stipulated. They do not follow from the word “values.”
values_context.axOpen in Playground ↗

Result: the seminar and quiet exam yield different candidates. Completing one action leaves the value assertion intact; withdrawing feasibility removes support for that candidate. This last check is more informative than simply printing a recommendation: it shows which assumption makes the result depend on the situation.

The policy neither ranks multiple candidates nor chooses someone’s values. It contains no rules about risk, coercion, conflicting commitments or long-term consequences. Those would require further predicates and justification. A program that silently equated “values-consistent” with “ethically justified” would add a normative claim that this model does not establish.

What running this establishes. Candidate selection changes with context and feasibility; completing an act does not finish the continuing value.

05 · A HYPOTHESIS THAT CAN LOSE SUPPORT

Make the explanatory bridge visible

A theory may propose that changing a process helps change behavior. Such a proposal is not the same thing as a definition. Here we introduce an intentionally schematic bridge: if an intervention occurs and a mechanism is assumed for this case, tentatively predict engagement. This is our illustrative rule, not an estimated effect, a quotation from ACT, or a validated prediction for an individual.

AXIOMA MODEL · OUR RECONSTRUCTION

Translation choices
mechanism_assumed explicitly supports predicts_engagement.
Additional assumptions and scope
The toy bridge is ours, not a formal law supplied by these authors. The example demonstrates dependency management, not a mediation analysis.
revisable_prediction.axOpen in Playground ↗

Result: the prediction is a conjecture. Removing its mechanism premise removes its support while preserving the recorded intervention. We have tested the dependency, not refuted the mechanism. There is no numerical probability or automatic update from clinical data here; someone must justify adopting or withdrawing the premise.

This separation matters empirically. Arch and colleagues identify challenges in distinguishing and validating ACT process measures, inconsistent evidence about process specificity and mediation, and problems of power and transparency. [5] Their critique supplies questions for evaluating a causal bridge, not grounds to declare all ACT effects absent.

What running this establishes. Withdrawing the mechanism assumption removes the dependent prediction while retaining the intervention fact.

06 · KNOWLEDGE + PROGRAMMING

An outcome report is not a mechanism proof

Twohig and colleagues randomized 79 adults with OCD to eight sessions of ACT or progressive relaxation training (PRT). Their abstract reports greater improvement in OCD severity with ACT in this comparison. The pretreatment and posttreatment Y-BOCS means were 24.22 and 12.76 for ACT, and 25.40 and 18.67 for PRT. [6]

We store those four rounded means as source-indexed facts in hundredths of a scale point. A function queries the facts; a broadcast applies it to both arms and computes changes. This is a small example of using knowledge representation and ordinary numerical programming in the same language.

AXIOMA MODEL · OUR RECONSTRUCTION

Translation choices
reported_mean100 stores the published rounded means as exact hundredths.
Additional assumptions and scope
Calculations use aggregate rounded values; no participant data, uncertainty estimate or mechanism identification is available from this arithmetic.
evidence_arithmetic.axOpen in Playground ↗

Result: the descriptive decreases are 11.46 and 6.73 points; their difference is 4.73, calculated from the published rounded means. This arithmetic is not a standardized effect size, significance test, uncertainty estimate, or reanalysis of participant data. Exact fractions preserve the reported decimal precision; they do not make the measurements exact.

The trial concerns a particular population, comparator and outcome. It does not, by that fact alone, establish superiority to every alternative or identify which proposed process produced the change. The empty mechanism query only exposes the absence of such an inference in our model. Assessing mediation would require an appropriate design, measurements and analysis, rather than another unconditional rule. [5]

What running this establishes. The changes in the reported means can be reproduced. This calculation does not independently establish efficacy, statistical significance or the ACT mechanism.

FINDINGS · VERSION 0.1

What this reconstruction establishes

Within the model

Acceptance and action have compatible targets; context changes candidate actions; a withdrawn hypothesis removes a dependent prediction.

Not established

Clinical effectiveness in general, a causal mechanism, a diagnosis, or completeness of ACT as a psychological theory.

Next investigation

Operational definitions, competing mechanisms, temporal observations and evidence that could discriminate between them.

The main gain is an audit trail across three boundaries: source to premise, premise to consequence, and consequence to empirical interpretation. The first card makes adoption explicit. The middle cards test definitions and dependencies. The last card connects source-indexed knowledge to a numerical calculation without pretending that arithmetic settles explanatory questions.

The largest gap in the present reconstruction is operationalization. We named willingness, feasibility, values and engagement without measuring them. We did not formalize all six processes, relational learning, changes over time, competing reports, individual variation or treatment selection. The source set is selective, not a systematic review; no claim of exhaustive coverage or priority is made.

A useful next version would choose one narrow mechanism claim, locate its operational measures and relevant primary studies, represent an explicit alternative explanation, and specify which observations would favor either account. It would then check whether the same evidence is being reused as both a definition of improvement and evidence for its cause.

All six cards run independently in the current Axioma evaluator and browser interpreter. Automated tests extract these exact page examples and check their 25 assertions before publication. This verifies the executable model, not the adequacy of its psychological interpretation. The derivation vocabulary follows Axioma’s existing study of epistemic grounding.

SOURCES & ATTRIBUTION

References

References are numbered in order of first use. The bibliography identifies the material consulted; numbered links near substantive claims connect the prose to its source. All code, case facts, candidate policies and finite-model interpretations are this study’s reconstruction, not code or formal axioms supplied by the cited authors.

  1. Hayes, S. C., Luoma, J. B., Bond, F. W., Masuda, A., & Lillis, J. (2006). Acceptance and commitment therapy: Model, processes and outcomes. Behaviour Research and Therapy, 44(1), 1–25. doi:10.1016/j.brat.2005.06.006.
    Consulted: open author manuscript, especially “Six Core Processes of ACT.” The manuscript contains editorial placeholders elsewhere; definitions were cross-checked with [2].
  2. Association for Contextual Behavioral Science. (n.d.). The six core processes of ACT. Official ACT process descriptions. Accessed 6 September 2026. Consulted in full.
  3. Association for Contextual Behavioral Science. (n.d.). Functional contextualism. Official philosophical overview. Accessed 6 September 2026. Consulted in full.
  4. Axioma project. (2026). What a claim knows about itself and Epistemic justification. Runnable language semantics study; versioned justification reference. These document the implementation vocabulary used here, not evidence about ACT.
  5. Arch, J. J., Fishbein, J. N., Finkelstein, L. B., & Luoma, J. B. (2023). Acceptance and commitment therapy processes and mediation: Challenges and how to address them. Behavior Therapy, 54(6), 971–988. doi:10.1016/j.beth.2022.07.005. PubMed record.
    Consulted: indexed abstract and bibliographic record. The summary above is limited to the challenges listed in that abstract.
  6. Twohig, M. P., Hayes, S. C., Plumb, J. C., Pruitt, L. D., Collins, A. B., Hazlett-Stevens, H., & Woidneck, M. R. (2010). A randomized clinical trial of acceptance and commitment therapy versus progressive relaxation training for obsessive-compulsive disorder. Journal of Consulting and Clinical Psychology, 78(5), 705–716. doi:10.1037/a0020508. PubMed abstract and full-text links.
    Consulted: abstract. The four means reproduced above are reported there; no participant-level dataset was analyzed.

Inspect the premises. Run the consequences.

This first version opens an investigation: which parts of a psychological account are definitions, which are assumptions, and which require evidence?