Subject Sensitive Invariantism

Overview and Core Idea

Subject Sensitive Invariantism (SSI) is a view in contemporary epistemology and the theory of knowledge ascriptions. It maintains that the truth-conditions of sentences of the form “S knows that p” are invariant across conversational contexts—the word “knows” always means the same thing—but that whether a subject satisfies those conditions depends partly on the subject’s practical situation, such as what is at stake for them or what they are rationally required to do with the information.

On SSI, knowledge is “interest-relative”: a subject in a high-stakes situation may fail to know a proposition that the same subject, with the same evidence, would count as knowing in a low-stakes situation. This is not because the meaning of “knows” changes between conversations, but because the subject’s practical circumstances enter into the conditions for knowing.

SSI is typically classified as an instance of pragmatic encroachment in epistemology—the idea that pragmatic or practical factors encroach on purely epistemic states such as knowledge or justification—paired with a semantic invariantism about the knowledge predicate.

Motivations and Key Examples

Proponents of Subject Sensitive Invariantism are motivated by both intuitive cases and theoretical pressures in epistemology and the philosophy of language.

A central kind of case involves stakes-sensitive knowledge ascriptions. Consider:

• Low stakes case: Hannah and her partner are driving home on a Friday. They pass a bank and see that it appears open. They deposited a check there two weeks ago on a Saturday. Very little hinges on whether the bank will be open tomorrow; if they are wrong, it is only a minor inconvenience. Hannah says, “I know the bank will be open tomorrow.”

• High stakes case: In a variation, a large bill must be paid tomorrow. If the bank is closed, significant penalties will result. Hannah’s evidence is the same—she saw the bank open and recalls a recent Saturday deposit—but now a lot depends on being right. She hesitates and says, “I don’t know that the bank will be open tomorrow.”

Many people share the intuition that the low-stakes assertion “I know the bank will be open” is true or appropriate, while the high-stakes assertion “I know the bank will be open” is not. SSI attempts to respect these intuitions without appealing to context-dependent meanings for “knows”.

On an SSI account:

• In low stakes, Hannah’s evidence (perception and memory) suffices for knowledge.
• In high stakes, the very same evidence may no longer suffice, because the required epistemic position is stronger when much is at risk. For instance, she may need to rule out more alternatives, gather more evidence, or be in a position to act responsibly on the basis of p.

This can be generalized to other familiar cases:

• Lottery cases: You hold a ticket in a fair, large lottery. The probability that your ticket will lose is extremely high. In everyday life, you may say “I know I won’t win,” but some argue that in contexts where betting large sums on this proposition is at issue, it is inappropriate—or even false—to say you know your ticket will lose, because you still face a live possibility that it will win.

• Moral and legal decision-making: A doctor deciding on a high-risk treatment or a jury deliberating over a verdict might be thought to need a stronger epistemic position than someone making a trivial everyday prediction. SSI models this by making the subject’s decision problems and potential costs part of the conditions for knowledge.

Motivationally, SSI promises to explain why our ordinary patterns of knowledge attribution seem sensitive to stakes, while avoiding the claim that the meaning of “knows” changes between conversations.

Comparison with Rivals

Subject Sensitive Invariantism is typically contrasted with two other influential positions: classical invariantism and contextualism.

1. Classical Invariantism (non–subject-sensitive)
   Classical invariantists hold that:

   • The meaning of “knows” stays constant across contexts.
   • Only epistemic factors such as evidence, reliability, and truth determine whether a subject knows.
   • Practical interests are at most indirectly relevant (for example, by influencing which evidence the subject actually acquires), but do not themselves help constitute knowledge.

   Compared with this view, SSI adds a direct role for practical interests in determining knowledge, while keeping the invariantist semantic framework.

2. Contextualism about Knowledge Ascriptions
   Epistemic contextualists maintain that:

   • The truth-conditions of sentences like “S knows that p” vary with the attributor’s conversational context.
   • Different conversations can impose different epistemic standards; in skeptical or high-stakes discussions, the standard for “knows” is higher.
   • Knowledge itself (as a relation between subject and proposition) need not be interest-relative; rather, it is the attributor’s context that shifts what counts as knowledge.

   SSI differs in two main ways:

   • On SSI, the semantics of “knows” are fixed; it is instead the subject’s practical situation that matters.
   • For contextualism, two attributors in different contexts can truly say both “S knows that p” and “S does not know that p” about the same subject and evidence. For SSI, if both attributions are true, it is because the subject’s own practical situation changes, not the meaning of “knows”.

3. Other Forms of Pragmatic Encroachment
   There are also positions that accept pragmatic encroachment but do not adopt SSI’s invariantist semantics. Some maintain that:

   • Justification, rather than knowledge, is interest-relative.
   • The encroachment is best captured by a link between knowledge and rational action (for example, that one knows p only if it is rational to act on p in one’s circumstances), without committing to any particular semantic view of “knows”.

   SSI can be seen as a specific way of implementing pragmatic encroachment at the level of the truth-conditions of knowledge ascriptions.

Objections and Ongoing Debates

SSI has attracted substantial critical discussion. Objections tend to focus on three main areas: the nature of knowledge, semantic plausibility, and the normative implications of interest-relativity.

1. Purity of the Epistemic
   Some critics argue that making knowledge depend on practical interests undermines the idea that knowledge is a purely epistemic notion. They contend that:

   • Whether one knows should be a matter of having sufficient evidence or epistemic justification, not of the costs of being wrong.
   • Practical considerations properly affect what one ought to do, not what one knows.

   Proponents respond that knowledge is intimately connected to rational action: knowing p is, in part, being in a position where it is normally rational to rely on p in one’s practical reasoning; hence practical factors legitimately enter the picture.

2. Stability and “Shifty” Knowledge
   Another concern is that SSI makes knowledge seem too unstable: as a subject’s stakes fluctuate, the subject may gain or lose knowledge without any change in evidence. Some philosophers find it counterintuitive that simply raising the stakes can turn a true, well-supported belief from knowing into not knowing.

   Defenders reply that our ordinary judgments and conversational practices already treat knowledge as somewhat stakes-sensitive, and that SSI offers a principled explanation of this phenomenon rather than creating it.

3. Semantic and Psychological Concerns
   Critics also question whether SSI provides a plausible semantic account:

   • Some claim that ordinary speakers do not treat knowledge as explicitly interest-relative; they talk as though evidence and truth are what matter.
   • Others argue that the phenomena driving SSI can be explained by pragmatic features of assertion (such as the norms governing what one may assert) or by conversational implicatures, without building stakes into the truth-conditions of knowledge.

   In response, SSI advocates argue that explaining stakes effects merely at the level of assertion norms often fails to capture the truth-conditional intuitions people have in carefully constructed thought experiments.

4. Normative and Theoretical Implications
   SSI also interacts with broader debates about:

   • The relationship between knowledge and action, especially in decision theory and ethics.
   • Whether legal or moral standards of proof reflect an implicit form of interest-relative knowledge.
   • How to model rational belief, credence, and the threshold at which one moves from high probability to knowledge when practical costs are high.

Subject Sensitive Invariantism remains an influential and contested view in epistemology. It offers a distinctive way to integrate pragmatic considerations into an otherwise invariantist theory of knowledge, thereby occupying an intermediate space between classical invariantism and contextualism, and continues to shape debates about how closely epistemic concepts are tied to our practical lives.