Propositional and doxastic justification

Drawing on the results of previous chapters, the proposal is made to interpret the complex operator ⌜¬K¬K⌝ as encoding propositional justification and the complex operator ⌜¬K¬K⌝ as encoding doxastic justification—where in each case justification is understood to be justification all things considered. Accordingly, not only propositional but also doxastic justification is construed as a feature of one’s epistemic situation rather than a feature of one’s beliefs. On this view, both types of justification are non-factive. The proposed account is defended against a number of putative counterexamples, the allegation that it confuses epistemic permissibility with epistemic blamelessness, and the charge that it fails to heed plausible reliabilist constraints on justification. At crucial junctures this defence relies on the availability of theorems governing the aforementioned complex operators that were proved in chapter 5.

Competing views

The present account, which construes justification as a kind of epistemic possibility of knowing, or of being in a position to know, competes with three recently advanced theories of justification. Of these competitors, the first two construe doxastic justification as the metaphysical possibility of knowing. While they differ in some details, these views share certain problematic features: they fail to yield a corresponding account of propositional justification, have trouble vindicating an intuitive principle of closure for justified belief, and fail to comply with the independently plausible principle that if one has a justified belief, one is in no position to rule out that one has knowledge. The present account does not have these problematic features. According to the third competitor, |φ‎| is propositionally justified in one’s situation just in case it would be abnormal—and so require explanation—if |φ‎| were to be false in the presence of the evidence that one possesses in that situation. This normic theory of justification validates the principle that propositional justification agglomerates over conjunction, and in so doing, violates the constraint that propositions of the form ⌜φ‎ & ¬Kφ‎⌝ never be justified. It likewise contradicts the independently plausible principle that whenever |φ‎| is propositionally justified all things considered, |¬Kφ‎| is not. The present account does not face these problems, since it rejects the relevant agglomeration principle and treats the condition encoded by ⌜¬K¬Kφ‎⌝ as luminous.

Concluding Remarks

According to the account of epistemic justification developed in this book, one has propositional justification for p just in case one is in no position to know that one is in no position to know p; and one has doxastic justification for p just in case one is in no position to know that one does not know p. The account gives internalists much of what they want from a theory of justification—in particular, a notion of justification according to which propositional justification is non-factive and luminous, underwrites principles of positive and negative introspection, and remains available to the victims of systematic deception. All the while, that notion is explained in terms of other notions that clearly belong to the knowledge-firsters’ toolkit, and coheres with an externalist account of the grounds for justification.

Grounds for justification

We must distinguish between the condition of a proposition’s being justified in one’s situation and the metaphysical grounds determining that this condition obtains. While the former is luminous, the latter need not be. It is argued that knowing is a strict full ground for doxastic justification, and being in a position to know is a strict full ground for propositional justification. It follows that facts about one’s evidence that serve as strict partial grounds for knowing are strict partial grounds for doxastic justification, and facts about one’s evidence that serve as strict partial grounds for being in a position to know are strict partial grounds for propositional justification. Even if only partial, such evidential grounds can only be assumed to be available in some, but not all, cases in which one has doxastic justification without knowing, and propositional justification without being in a position to know. A more comprehensive account identifies facts about evidential probabilities as facts that yield strict full grounds for justification. While one’s evidence is the totality of what one is in a position to know, the evidential probability of p equals the probability of p conditional on one’s evidence. The account requires taking the notion of evidential probability as primitive. It uniformly applies to all cases of justification, including the bad cases envisaged by radical scepticism. Degrees of strength of justification are explained in terms of facts about evidential probabilities. Just as their grounds, degrees of strength of justification are not luminous, even if justification is.

Applications

To earn their keep, theories of justification must be shown to have fruitful applications and to provide the means to address well-known puzzles and paradoxes. It is argued that the present account of justification does very well on this score. Not only does it prove amenable to the idea that standards for knowledge and justification may shift, it allows for an explanation of why they shift in tandem. It lends itself to a justificationist conception of the rules that may guide the formation of beliefs, to the extent that these beliefs aspire to be knowledgeable. The present account moreover affords principled solutions to the preface paradox, the lottery paradox, the related but distinct lottery puzzle, and a more recent sceptical challenge targeting doxastic justification.

Degrees of Doxastic Justification

This paper studies degrees of doxastic justification. Dependency relations among different beliefs are represented in terms of causal models. Doxastic justification, on this picture, is taken to run causally downstream along appropriate causal chains. A theory is offered which accounts for the strength of a derivative belief in terms of (i) the strength of the beliefs on which it is based, and (ii) the epistemic quality of the belief-forming mechanisms involved. It is shown that the structure of degrees of justification converges to ranking theory under ideal conditions.

How Racial Injustice Undermines News Sources and News-Based Inferences

I argue racial injustice undermines the reliability of news source reports in the information domain of racial injustice. I argue that this in turn undermines subjects’ doxastic justification in inferences they base on these news sources in the racial injustice information domain. I explain that racial injustice does this undermining through the effect of racial prejudice on news organizations’ members and the effect of society's racially unjust structure on non-dominant racial group-controlled news sources.

On the Relationship between Propositional and Doxastic Justification

I argue against the orthodox view of the relationship between propositional and doxastic justification. The view under criticism is: if p is propositionally justified for S in virtue of S’s having reason(s) R, and S believes p on the basis of R, then S’s belief that p is doxastically justified. I then propose and evaluate alternative accounts of the relationship between propositional and doxastic justification, and conclude that we should explain propositional justification in terms of doxastic justification. If correct, this proposal would constitute a significant advance in our understanding of the sources of epistemic justification.

An Infinitist Account of Doxastic Justification

Any satisfactory epistemology must account for the distinction between propositional and doxastic justification. This paper advances a new infinitist account of the distinction.