Legal certainty is frequently associated with the idea that legal subjects must be able to anticipate how their actions will be classified by the legal system. Yet, as soon as the notion of predictability is analysed with rigour, the apparently simple intuition proves far more demanding than it initially appears. Predictability can only operate as a criterion of legal certainty if a series of conceptual, epistemic and methodological commitments are explicitly adopted. Without these commitments, appeals to predictability remain superficial and inert.
This series of blogposts reconstructs those some of the principal commitments. We will start, in this Part I, with two of them: (1) commitment to beneficiaries and predictors; and (2) commitment to a methodology of prediction.
Commitment to Beneficiaries and Predictors: Fixing the Epistemic Point of View
A predictabilist position requires clarifying whose perspective grounds the relevance of predictability and whose epistemic capacities determine whether a system is predictable. Predictability is not a property of the legal system in abstraction; it is always predictability for a specific agent, situated in a particular cognitive environment.
Who is the beneficiary?
Different beneficiaries face different informational needs.
If the beneficiary is the ordinary citizen, predictability presupposes that the system provides stable public signals: a transparent normative communication environment that enables agents without specialised knowledge to anticipate the legal consequences of their actions. Predictability, here, is tied to the public intelligibility of law.
If the beneficiary is the practising lawyer, predictability must operate over a substantially richer epistemic structure. Lawyers require familiarity with interpretive patterns, recurring lines of doctrine, implicit argumentative hierarchies, and the institutional habits of courts. Predictability becomes inseparable from access to a stable interpretive culture.
If the beneficiary is the legislator, predictability functions as a condition for rational rulemaking: the legislator must be capable of anticipating how new provisions will be interpreted, how they will interact with existing norms, and how adjudicators will classify relevant facts.
Judges may also be considered beneficiaries. Predictability is, for them, a dimension of institutional self-coordination: the ability to foresee how colleagues will decide similar cases in order to maintain coherence and avoid doctrinal fragmentation.
Scholars constitute another possible beneficiary. For them, predictability relates to the capacity to reconstruct jurisprudential evolution, identify latent patterns and diagnose structural inconsistencies.
Who is the predictor?
Alongside beneficiaries comes the predictor. A predictabilist approach requires committing to a hierarchy of epistemic authority: whose predictive judgements track the system faithfully?
Citizens, practitioners, judges, and academics all stand in different epistemic relations to the system. Predictability is a relational property, and the theory must specify which relations are normatively appropriate for assessing legal certainty.
What dimension of predictability?
Predictability also has both an ex-ante and an ex-post dimension.
- Ex-ante, beneficiaries require a position from which theycan form reasonable expectations.
- Ex post, those expectations must be evaluable – one must be capable of determining whether such expectations were eventually confirmed.
A full predictabilist approach requires adopting commitments for both.
Commitment to a Methodology of Prediction: Inputs, Procedures, Correctness, Feasibility
A second commitment concerns methodology. Predictions do not emerge spontaneously; they require procedures grounded in identifiable inputs and justification standards.
A predictabilist approach requires specifying:
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- Informational inputs: which sources are normatively relevant for prediction (case law, doctrinal debates, institutional practices, interpretive canons, social expectations).
- Form of analysis: whether predictions aim to be specific (high-precision forecasts) or generic (predicting ranges of possibilities)
- Criteria of correctness: whether predictive adequacy is probabilistic, dispositional, abductive, or based on interpretive reasoning.
- Institutional feasibility: predictability presupposes that a system has the infrastructural capacity—transparency, publication, doctrinal stability—to sustain predictive practices.
Without these methodological commitments, predictability remains speculative rather than epistemically grounded.
Coming up next
We have seen here two commitments of predictability, related to agents and contexts, as well as methodology. Is this enough, however?
Of course not!
In Part II, we will see the commitment related to mandates or outcomes (deciding on the object of the prediction), and in Part III, we will see the commitment related to predictions as epistemic tools.
To read more about this and engage in the discussion, check out this recent paper: García Yzaguirre, V. (2024). Seguridad jurídica y predictibilidad: Una propuesta de reconstrucción. Archiv für Rechts- und Sozialphilosophie [LINK]. You can also check out the author’s previous published work on the same topics. [LINK]
SUGGESTED CITATION: García-Yzaguirre, Víctor: “Legal Certainty and the Commitments of Predictability (Part I)”, FOLBlog, 2025/12/01, https://fol.ius.bg.ac.rs/2025/12/01/legal-certainty-and-the-commitments-of-predictability-part-i/