Active Information, Learning, and Knowledge Acquisition

Philosophers frequently define knowledge as justified, true belief. In this paper we build a mathematical framework that makes possible to define learning (increased degree of true belief) and knowledge of an agent in precise ways. This is achieved by phrasing belief in terms of epistemic probabilities, defined from Bayes' Rule. The degree of true belief is then quantified by means of active information $I^+$, that is, a comparison between the degree of belief of the agent and a completely ignorant person. Learning has occurred when either the agent's strength of belief in a true proposition has increased in comparison with the ignorant person ($I^+>0$), or if the strength of belief in a false proposition has decreased ($I^+<0$). Knowledge additionally requires that learning occurs for the right reason, and in this context we introduce a framework of parallel worlds, of which one is true and the others are counterfactuals. We also generalize the framework of learning and knowledge acquisition to a sequential setting, where information and data is updated over time. The theory is illustrated using examples of coin tossing, historical events, future events, replication of studies, and causal inference.

Evidence of Factive Norms of Belief and Decision

According to factive accounts of the norm of belief and decision-making, you should not believe or base decisions on a falsehood. Even when the evidence misleadingly suggests that a false proposition is true, you should not believe it or base decisions on it. Critics claim that factive accounts are counterintuitive and badly mischaracterize our ordinary practice of evaluating beliefs and decisions. This paper reports four experiments that rigorously test the critic’s accusations and the viability of factive accounts. The results undermine the accusations and provide the best evidence yet of factive norms of belief and decision-making. The results also help discriminate between two leading candidates for a factive norm: truth and knowledge. Knowledge is the superior candidate.

Golden Gettier

Gettier constructed his well-known examples by assuming two things: (1) that the justification needed to know is the kind one can have for a false proposition; and (2) justificational closure— that justification is transmitted through known implication. I think both assumptions are false. Although I have elsewhere disputed (2), I will set that topic aside here. In this chapter I will, instead, challenge (1) by showing that if you accept (2), or any reasonable approximation to (2), you cannot accept (1). The justification needed to know must be conclusive, the kind of justification one cannot have for a false proposition.

Truth, Sense and Assertion

Protagoras and his pupil Euthalos argued against one another in paradoxical fashion regarding the fulfilment of a contract. Protagoras was a Sophist, the first European inventors of logical puzzles who also argued that there cannot be false thinking. A paradox, however, does not say anything, and there is no solution to the question as to who is right in the exchange between Protagoras and Euthalos. On the other hand there is a real question as to how it is that a false proposition makes sense, and the Sophists were right in as much as a false proposition, while it does say something does not, being believed, tell its believer anything. The exclusion of paradoxical propositions is not to be achieved, as Russell supposed, by applying some general principle; rather matters need arguing through in particular cases as they arise.

Richard Kilvington and the Theory of Obligations

Kretzmann and Spade were led by Richard Kilvington’s proposed revisions to the rules of obligations in his discussion of the 47th sophism in his Sophismata to claim that the purpose of obligational disputations was the same as that of counterfactual reasoning. Angel d’Ors challenged this interpretation, realising that the reason for Kilvington’s revision was precisely that he found the art of obligation unsuited to the kind of reasoning that lay at the heart of the sophismatic argument. In his criticism, Kilvington focused on a technique used by Walter Burley to force a respondent to grant an arbitrary falsehood and similar to Lewis and Langford’s famous defence of ex impossibili quodlibet. Kilvington observed that just as in obligational disputation one may be obliged to grant a false proposition and deny a true one, so in counterfactual reasoning one may be obliged to doubt a proposition whose truth or falsity one knows, on pain of contradiction.

Knowledge despite falsehood

I examine the claim, made by some authors, that we sometimes acquire knowledge from falsehood. I focus on two representative cases in which a subject S infers a proposition q from a false proposition p. If S knows that q, I argue, S’s false belief that p is not essential to S’s cognition. S’s knowledge is instead due to S’s belief that p′, a proposition in the neighbourhood of p that S (dispositionally) believes (and knows). S thus knows despite her false belief. The widely accepted and plausible principle that inferential knowledge requires known premises is unscathed.

MINIMALISM AND THE LIMITS OF WARRANTED ASSERTABILITY MANEUVERS

Contextualists and pragmatists agree that knowledge-denying sentences are contextually variable, in the sense that a knowledge-denying sentence might semantically express a false proposition in one context and a true proposition in another context, without any change in the properties traditionally viewed as necessary for knowledge. Minimalists deny both pragmatism and contextualism, and maintain that knowledge-denying sentences are not contextually variable. To defend their view from cases like DeRose and Stanley's high stakes bank case, minimalists like Patrick Rysiew, Jessica Brown, and Wayne Davis forward ‘warranted assertability maneuvers.’ The basic idea is that some knowledge-denying sentence seems contextually variable because we mistake what a speaker pragmatically conveys by uttering that sentence for what she literally says by uttering that sentence. In this paper, I raise problems for the warranted assertability maneuvers of Rysiew, Brown, and Davis, and then present a warranted assertability maneuver that should succeed if any warranted assertability maneuver will succeed. I then show how my warranted assertability maneuver fails, and how the problem with my warranted assertability maneuver generalizes to pragmatic responses in general. The upshot of my argument is that, in order to defend their view from cases like DeRose and Stanley's high stakes bank case, minimalists must prioritize the epistemological question whether the subjects in those cases know over linguistic questions about the pragmatics of various knowledge-denying sentences.

A NEW EPISTEMIC UTILITY ARGUMENT FOR THE PRINCIPAL PRINCIPLE

Jim Joyce has presented an argument for Probabilism based on considerations of epistemic utility. In a recent paper, I adapted this argument to give an argument for Probablism and the Principal Principle based on similar considerations. Joyce's argument assumes that a credence in a true proposition is better the closer it is to maximal credence, whilst a credence in a false proposition is better the closer it is to minimal credence. By contrast, my argument in that paper assumed (roughly) that a credence in a proposition is better the closer it is to the objective chance of that proposition. In this paper, I present an epistemic utility argument for Probabilism and the Principal Principle that retains Joyce's assumption rather than the alternative I endorsed in the earlier paper. I argue that this results in a superior argument for these norms.

The Afterlife of Oyono's Houseboy in the Swahili Schools Market: To Be or Not to Be Faithful to the Original

Africa, the world's second-largest continent, speaks over two thousand languages but rarely translates itself. it is no wonder, therefore, that Ferdinand Oyono's francophone African classic Une vie de boy (1956), translated into at least twelve European and Asian languages, exists in only one African translation—that is, if we consider as non-African Oyono's original French and the English, Arabic, and Portuguese into which it was translated. Since 1963, when Obi Wali stated in his essay “The Dead End of African Literature” that African literature in English and French was “a clear contradiction, and a false proposition,” like “Italian literature in Hausa” (14), the question of the language of African literature has animated debate. Two decades later, Ngũgĩ wa Thiong'o restated Wali's contention, asserting that European languages led to African “spiritual subjugation” (9). Ngũgĩ argued strongly that African literature should be written in African languages. On the other hand, Chinua Achebe defended European languages, maintaining that they could “carry the weight of African experience” (62).

The reality of lies

A lie is neither a false proposition, nor a mistake, nor a mere fiction; it is a type of fiction, an act, and precisely an intentional act. An act calls for a subject, and therefore a lie is inseparable from its subject. Together, they make up a real object: it has to be real, since a lie produces effects, and the cause-effect relationship only holds between real beings. Like every real object, a lie unfolds in a (phenomenological) context. But there is more: it identifies a (dialectical) context.