Externalism about some mental property, M, is the thesis that whether a person (or other physical being) has M depends, not only on conditions inside the person.

In this paper I will argue that Boghossian's explanation of how we can acquire a priori knowledge of logical principles through implicit definitions commits a transmission of warrant-failure. To this end, I will briefly outline Boghossian's account, followed by an explanation of what a transmission of warrant-failure consists in. I will also show that this charge is independent of the worry of rule-circularity which has been raised concerning the justification of logical principles and of which Boghossian is fully aware. My (...) argument comes in two steps: firstly, I will argue for the insufficiency of Boghossian's template which is meant to explain how a subject can acquire a warrant for logical principles. I will show however that this insufficiency of his template can be remedied by adopting what I call the Disquotational Step. Secondly, I will argue that incorporating this further step makes his template subject to a transmission of warrant-failure, assuming that certain rather basic and individually motivated principles hold. Thus, Boghossian's account faces a dilemma: either he adopts the Disquotational Step and subjects his account to the charge of a transmission of warrant-failure, or he drops this additional step leaving the account confronted with explaining the gap that has previously been highlighted. I will then suggest various rejoinders that Boghossian might adopt but none of which - I will argue - can resolve the dilemma. Lastly, I will raise and briefly discuss the question whether this worry generalizes to other accounts, such as Hale and Wright's that aim to explain our knowledge of logic and/or mathematics in virtue of implicit definitions. (shrink)

In my 1991 paper, AAnti-Individualism and Privileged Access,@ I argued that externalism in the philosophy of mind is incompatible with the thesis that we have privileged , nonempirical access to the contents of our own thoughts.¹ One of the most interesting responses to my argument has been that of Martin Davies (1998, 2000, and Chapter _ above) and Crispin Wright (2000 and Chapter _ above), who describe several types of cases to show that warrant for a premise does not always (...) transmit to a known deductive consequence of that premise, and who contend that this fact under-mines my argument for incompatibilism. I will try to show here that the Davies/Wright point about transmission of warrant does not adversely affect my argument. (shrink)

According to Wright, Moore’s contentious “proof of the existence of a material world” in not cogent because no warrant can transmit from its premise to its conclusion. Since Bayesian confirmation theory probably affords the best account of inductive reasoning we have today, if Wright’s analysis of Moore’s “proof” could be translated in Bayesian language, it would probably be preferable to rival analyses that cannot be reformulated in the same way. Okasha has recently proposed a Bayesian model that apparently vindicates Wright’s (...) analysis on the whole. In this paper I first argue that Okasha’s Bayesian vindication is in different respects flawed and thus unacceptable. I then propose a more suitable Bayesian framework, resting on the so-called Lockean Thesis, which does vindicate Wright’s analysis. My investigation sheds new lights on the logical features proper to the warrant that Wright deems not to transmit across entailment, on the constituents of the logical “mechanism” that according to Wright engenders failure of transmission, and on the fine structure of the rational architecture of perceptual warrant outlined by Wright. (shrink)

I argue that Moore’s controversial proof of the existence of the world is justification-transmissive if epistemic justification is interpreted as incremental confirmation and some standard and intuitive assumptions are made. My argument crucially relies on Shogenji’s theorem of transitivity of probabilistic support.

Crispin Wright has introduced a principle of failure of transmission of warrant (or epistemic justification) across known entailment in the context of discussion of topics of epistemology and philosophy of mind. Formal epistemologists have struggled to turn Wright’s informal explanation of transmission failure into cogent Bayesian reasoning. In this paper I analyse two Bayesian models of Wright’s account recently proposed by Samir Okasha and Jake Chandler. I show that both models are inapt to formalize Wright’s explanation. After that, I lay (...) down a new Bayesian model that vindicates Wright’s explanation in full. (shrink)

Crispin Wright has introduced a principle of failure of transmission of warrant across entailment in the context of discussion of topics of epistemology and philosophy of mind. Formal epistemologists have struggled to turn Wright’s informal explanation of transmission failure into cogent Bayesian reasoning; no successful formalization has yet been produced. In this paper I lay down a very simple Bayesian model that appears to vindicate Wright’s explanation in full.

Consider the following well-worn example, first put forward by Fred Dretske. You’re at the zoo, and in the pen in front of you is a striped horse-like animal. The sign on the pen says “Zebra.” Assuming that animal really is a zebra, it would seem that your evidence is perfectly adequate to enable you to know that it’s a zebra. So you know.

Consider the argument: Circus-1 Men in clown suits are handing out tickets. So, probably: Circus-2 There’s a circus in town. So: Circus-3 There’s an entertainment venue in town. Presumably you’d be able to warrantedly believe Circus-2 on the basis of Circus-1. And we can suppose you’re reasonably certain that wherever there are circuses, there are entertainment venues. So you’d seem to be in a position to reasonably go on to infer Circus-3.

I set out the standard view about alleged examples of failure of transmission of warrant, respond to two cases for the view, and argue that the view is false. The first argument for the view neglects the distinction between believing a proposition on the basis of a justification and merely having a justification to believe a proposition. The second argument for the view neglects the position that one 9s justification for believing a conclusion can be one 9s premise for the (...) conclusion, rather than simply one 9s justification for the premise. Finally, the view is false since it is inconsistent with the closure of knowledge as closure is properly understood. (shrink)

In this paper I draw attention to a peculiar epistemic feature exhibited by certain deductively valid inferences. Certain deductively valid inferences are unable to enhance the reliability of one's belief that the conclusion is true—in a sense that will be fully explained. As I shall show, this feature is demonstrably present in certain philosophically significant inferences—such as GE Moore's notorious 'proof' of the existence of the external world. I suggest that this peculiar epistemic feature might be correlated with the much (...) discussed phenomenon that Crispin Wright and Martin Davies have called 'transmission failure'—the apparent failure, on the part of some deductively valid inferences to transmit one's justification for believing the premises. (shrink)