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.
We have already explored three commitments of predictability: in Part I, two commitments related to agents and contexts, and to methodology; in Part II, a commitment related to mandates or outcomes. Here, in Part III, we will explore a final commitment: the related to predictions as epistemic tools.
Commitment to Predictions as Epistemic Tools: Structure, Validity, Reflexivity, and Information
The third commitment concerns the notion of prediction itself. A predictabilist conception of legal certainty presupposes that members of a legal community have access to adequate information that allows them to anticipate future actions and states of affairs. In practice, this information is mediated by predictions about how legal decision-makers are likely to act when confronted with normative problems. The role of these predictions is not merely decorative: they are the vehicles through which agents convert present information into future-oriented expectations that can guide decision-making.
Prediction must be situated within the constraints of legal cognoscibility. Any serious predictabilist programme must reckon with familiar problems: the indeterminacy and open texture of legal language; the existence of normative gaps and logical or pragmatic inconsistencies; the unreliability of information about how norms are interpreted and used in practice (because of an ineffective law, erratic judicial habits, retroactive legislation, or opaque reasoning); and the lack of fully satisfactory techniques for identifying the ratio decidendi of many decisions. These are not marginal difficulties; they define the outer limits of any attempt to turn predictability into an ideal of legal certainty.
Crucially, they do not make prediction impossible. Rather, they show that the only viable ideal of a “good predictor” is one that recognises these obstacles and incorporates ways of dealing with them. Any conception of legal predictability must therefore understand predictions as fallible, context-sensitive tools, shaped by epistemic limitations and methodological choices, rather than as approximations to an impossible omniscience.
Predictions as Practical Devices
Legal predictions can serve both descriptive and prescriptive purposes. Descriptively, they help identify the range of options available to a person and the likely consequences of each course of action: they answer questions such as “If I litigate this claim, what are the plausible outcomes?” or “If this administrative authority adopts a certain policy, how are courts likely to react?”. Prescriptively, they are used to design strategies for making the world come closer to one’s evaluative preferences: they inform decisions about when to litigate, when to settle, how to argue, or which reforms to propose. In both guises, predictions are practical: they are meant to guide conduct.
This practical character distinguishes them from what might be called purely theoretical predictions, which are formulated within a theoretical framework in order to test its correctness. Theoretical predictions combine (a) information about specific circumstances, (b) a general regularity posited by a theory, and (c) a future-oriented statement derived from those premises; their success or failure serves to confirm or undermine the underlying theory. In the context of legal certainty, this is not the central role of prediction. What matters, rather, is the practical form: predictions that are (i) informative in the present about possible future facts, (ii) fallible, in the sense that their correctness depends on whether the predicted fact actually occurs, and (iii) usable as inputs in deliberation about what to do or omit.
The requirement that predictions be informative also sets a limit on what counts as predictability for purposes of legal certainty. Only future events that are, in principle, predictable can enter the assessment. An unpredictable event may remain such for at least two reasons. It may be methodologically unpredictable, because we lack the time, resources or tools to interpret the available information in a way that would support a forecast. Or it may be epistemically unpredictable, because the information that would have been necessary simply cannot be obtained. An event that is unpredictable in this strong sense does not count against legal certainty; one cannot demand the impossible. By contrast, a future event that was predictable in principle, but was not in fact predicted because the relevant information was not collected, processed or communicated, may well reveal a shortcoming of the system’s informational architecture.
Predictions as Reflexive Social Practices
Legal predictions are not only practical; they are reflexive. Once formulated and communicated, they can influence the very behaviour they purport to anticipate. This is a familiar feature of predictions in the social sciences: unlike in many natural phenomena, here the object of prediction is capable of reading, interpreting and reacting to the prediction itself.
Consider a simple example. A new statute on residential leases is enacted. Within weeks, leading private law scholars publish commentaries in which they forecast how courts are likely to interpret the statute and what may happen to landlords and tenants in different litigation scenarios. These publications have at least two effects. They enrich the set of interpretive possibilities by articulating and systematising readings that might otherwise have remained latent or dispersed. And they can influence the content of judicial decisions, precisely because courts sometimes adopt, adapt or react against the interpretive options that scholars have put on the table. In this sense, the publication of predictions helps shape the practice that is being predicted.
The degree of reflexive impact depends on several variables. A prediction may remain private—never leaving the mind of the predictor or the confines of a confidential conversation—in which case its effects are limited to the actions of that agent. Or it may be published and become accessible to a broader audience, generating expectations among those who read it. The extent to which those expectations influence behaviour depends, among other things, on how accessible the prediction is (for example, a blog post in a widely read outlet versus an obscure internal memo), on its perceived credibility (grounded in the author’s reputation or in the transparency and rigour of the method used), and on the attitudes of the intended beneficiaries towards the predictor and the predicted scenario.
Once a prediction is in circulation, the expectations it generates can play different roles. Sometimes they act as one more reason to be considered in practical deliberation. An adjudicator, for instance, may see that a respected commentator has predicted a certain interpretive outcome and treat that prediction as a consideration that increases or decreases the attractiveness of that outcome. In other cases, expectations may become a causal determinant of behaviour, turning the prediction into a self-fulfilling prophecy. If, for example, a judge decides to resolve a dispute exactly as a widely publicised predictive model suggests other judges will, in order to align with an anticipated mainstream and minimise the risk of reversal, the prediction becomes one of the causes of its own truth.
From the standpoint of legal certainty, this reflexivity is ambivalent. On the one hand, it highlights the practical importance of credible predictive practices: well-founded forecasts may contribute to stabilising expectations and to reducing arbitrary dispersions in adjudication. On the other hand, it shows that “success” in prediction does not always track epistemic accuracy. A prediction may be successful because it was causally efficacious, not because it was independently correct. Any predictabilist theory that equates accuracy with mere convergence between prediction and outcome, without reconstructing the causal chain, risks mistaking influence for knowledge.
Genuine Predictions, Normative Smuggling, and Direction of Fit
The reflexive and practical nature of legal predictions requires a further distinction between genuine and false predictions. Genuine predictions, even when shaped by theoretical and ideological presuppositions, aim to inform us about how the legal practice may in fact evolve. They exhibit a word-to-world direction of fit: their correctness depends on whether the world will later conform to what was said. They can succeed or fail; failure does not mean that no prediction was made, only that the forecast did not match the subsequent facts.
False predictions, by contrast, are not genuinely informative. They use the surface grammar of prediction but function, in substance, as directives to legal actors, especially adjudicators, about how they ought to decide. They have a world-to-word direction of fit: their implicit claim is not “this is what will happen”, but “this is what should happen, and it will only count as correct if the world is brought into line with what I have said”. This phenomenon is sometimes connected to the idea that predictions should operate as criteria of correctness for judicial activity. On that view, security is achieved if, and only if, adjudicators act so as to make the predictions of certain agents come true. The “prediction” thereby becomes a disguised standard of evaluation.
These false predictions are prescriptive judgements about how legal actors should behave, smuggled in under the language of forecasting. One of their main risks is that they can obscure both the responsibility and the ideological position of the author. By presenting a preferred future as if it were an inevitable outcome of the system, the predictor conceals his or her role in shaping that outcome. If the prediction becomes widely accepted as a benchmark of correctness, the line between describing and prescribing is blurred, and the vocabulary of predictability becomes an instrument of normative control rather than a tool of epistemic assessment.
False predictions, in this sense, are distinct from self-fulfilling prophecies. A self-fulfilling prediction is one whose publication is a causal factor in the occurrence of the predicted event. It may be epistemically well or poorly grounded; what matters is its causal impact. The hallmark of a false prediction, by contrast, is not its causal role but its lack of informative content: it does not offer a fallible, revisable estimate of what could happen, but an encoded injunction about what legal actors ought to bring about.
Predictions Require Adequate Information: Transparency and Access
Predictions contribute to legal certainty only if they are grounded in adequate information. This requires access to:
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- judicial decisions and their reasoning.
- doctrinal and interpretive materials.
- institutional practices and incentives.
- factual backgrounds and socio-normative contexts.
Predictability becomes structurally impossible where decisions are unpublished, reasoning is opaque, or interpretive methods lack stability. A predictabilist account therefore commits to an informational ecology that sustains prediction.
The Object of Prediction: Methods, Norms, Facts, and Consequences
Predictions need not concern outcomes alone. They may focus on:
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- the interpretive method likely to be adopted (textual, purposive, systemic, analogical).
- the norm to be applied or prioritised.
- the categorisation of facts.
- the legal consequence triggered by such categorisation, or
- the justified non-application of a precedent.
Each type has different epistemic demands and contributes differently to legal certainty. A predictabilist must therefore clarify which objects of prediction are relevant within their evaluative framework.
An overall conclusion
A predictabilist conception of legal certainty demands a rich and intricate architecture of commitments. It requires clarifying the standpoint of beneficiaries and predictors; distinguishing between predictability of mandates, outcomes, and authorised non-application; articulating a theory of prediction that accounts for direction of fit, reflexivity and information; and adopting a methodology capable of producing reliable predictive judgements.
Once these commitments are made explicit, predictability becomes a rigorous analytical framework rather than a rhetorical slogan, enabling a deeper understanding of the epistemic conditions under which legal certainty may be said to exist.
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 III)”, FOLBlog, 202/01/19, https://fol.ius.bg.ac.rs/2026/01/19/legal-certainty-and-the-commitments-of-predictability-part-iii/