Conversational Implicatures and Cancellability

In this paper I argue against a criticism by Matthew Weiner to Grice’s thesis that cancellability is a necessary condition for conversational implicature. I argue that the purported counterexamples fail because the supposed failed cancellation in the cases Weiner presents is not meant as a cancellation but as a reinforcement of the implicature. I moreover point out that there are special situations in which the supposed cancellation may really work as a cancellation.

True Antecedents

In this note I discuss what seems to be a new kind of counterexample to Lewis’s account of counterfactuals. A coin is to be tossed twice. I bet on ‘Two heads’, and I win. Common sense says that (1) is false. But Lewis’s theory says that it is true. (1) If at least one head had come up, I would have won.

A Critique of Armstrong’s Truthmaking Account of Possibility

In this paper I argue against Armstrong’s recent truthmaking account of possibility. I show that the truthmaking account presupposes modality in a number of different ways, and consequently that it is incapable of underwriting a genuine reduction of modality. I also argue that Armstrong’s account faces serious difficulties irrespective of the question of reduction; in particular, I argue that his Entailment and Possibility Principles are both false.

Sperm, Eggs and Hunks: Biological Origins and Identity

In several publications Graeme Forbes has developed and defended one of the strongest arguments for essentialism about biological origins. I attempt to show that there are deep, as yet unrecognized, problems with this argument. The problems with Forbes’s argument suggest that a range of other arguments for various forms of origin essentialism are also likely to be flawed, and that we should abandon the seemingly plausible general metaphysical thesis that concrete entities that share all intrinsic properties are identical.

Margins for Error and Sensitivity: What Nozick Might Have Said

Timothy Williamson has provided damaging counterexamples to Robert Nozick’s sensitivity principle. The examples are based on Williamson’s anti-luminosity arguments, and they show how knowledge requires a margin for error that appears to be incompatible with sensitivity. I explain how Nozick can rescue sensitivity from Williamson’s counterexamples by appeal to a specific conception of the methods by which an agent forms a belief. I also defend the proposed conception of methods against Williamson’s criticisms.

Qualia and the Argument from Illusion: A Defence of Figment

This paper resurrects two discredited ideas in the philosophy of mind. The first: the idea that perceptual illusion might have something metaphysically significant to tell us about the nature of phenomenal consciousness. The second: that the colours and other qualities that ‘fill’ our sensory fields are occurrent properties (rather than representations of properties) that are, nevertheless, to be distinguished from the ‘objective’ properties of things in the external world. Theories of consciousness must recognize the existence of what Daniel Dennett mockingly labels ‘figment,’ but this result—though metaphysically and epistemologically significant—is not incompatible with either physicalism or naturalized semantics.

Conceptualism and the Problem of Illusory Experience

According to the conceptualist view in the philosophy of perception, we possess concepts for all the objects, properties, and relations which feature in our experiences. Richard Heck has recently argued that the phenomenon of illusory experience provides us with conclusive reasons to reject this view. In this paper, I examine Heck’s argument, I explain why I think that Bill Brewer’s conceptualist response to it is ineffective, and I then outline an alternative conceptualist response which I myself endorse. My argument turns on the fact that both Heck, in constructing his objection to conceptualism, and Brewer, in responding to it, miss a crucial distinction between perceptual demonstrative concepts of objects, on the one hand, and perceptual demonstrative concepts of properties, on the other.

No Lacuna and No Vicious Regress: A Reply to Le Poidevin

In his “Space, supervenience and substantivalism”, Le Poidevin proposes a substantivalism in which space is discrete, implying that there are unmediated spatial relations between neighboring primitive points. This proposition is motivated by his concern that relationism suffers from an explanatory lacuna and that substantivalism gives rise to a vicious regress. Le Poidevin implicitly requires that the relationist be committed to the “only x and y” principle regarding spatial relations. It is not obvious that the relationist is committed to this principle in such a context. An additional motivation for Le Poidevin's argument, that space should be considered to be discrete, is that he believes that substantivalists are committed to a vicious regress. I show that the regress is in fact not of the vicious variety. These two main arguments show that Le Poidevin's suggestion that we drop the density postulate for space is unnecessary.

Nonbelief and the Desire-As-Belief Thesis

I show the incompatibility of two theses: (a) to desire the truth of p amounts to believing a certain proposition about the value of p’s truth; (b) one cannot be said to desire the truth of p if one believes that p is true. Thesis (a), the Desire-As-Belief Thesis, has received much attention since the late 1980s. Thesis (b) is an epistemic variant of Socrates’ remark in the Symposium that one cannot desire what one already has. It turns out that (a) and (b) cannot both be true if it is possible for there to exist an agent who has a desire initially, say the desire for the truth of p, and then expands the corpus of propositions she believes to include p. This result provides a new route to the denial of (a).

Anomaly detection in a mobile communication network

Mobile communication networks produce massive amounts of data which may be useful in identifying the location of an emergency situation and the area it affects. We propose a one pass clustering algorithm for quickly identifying anomalous data points. We evaluate this algorithm’s ability to detect outliers in a data set and describe how such an algorithm may be used as a component of an emergency response management system.

Is Believing at Will ‘Conceptually Impossible’?

In this paper I discuss the claim that believing at will is ‘conceptually impossible’ or, to use a formulation encountered in the debate, “that nothing could be a belief and be willed directly”. I argue that such a claim is only plausible if directed against the claim that believing itself is an action-type. However, in the debate, the claim has been univocally directed against the position that forming a belief is an action-type. I argue that the many arguments offered in favor of the ‘conceptual impossibility’ of performing such actions fail without exception. If we are to argue against doxastic voluntarism we are better off by resorting to more modest means.

Computational Construction as a Means to Coordinate Representations of Infinity

In this paper, we describe a design experiment aimed at helping students to explore and develop concepts of infinite processes and objects. Our approach is based on the design and development of a computational microworld, which afforded students the means to construct a range of representational models (symbolic, visual and numeric) of infinity-related objects (infinite sequences, in particular). We present episodes based on four students’ activities, seeking to illustrate how the available tools mediated students’ understandings of the infinite in rich ways, allowing them to discriminate subtle process-oriented features of infinite processes. We claim that the microworld supported students in the coordination of hitherto unconnected or conflicting intuitions concerning infinity, based on a constructive articulation of different representational forms we name as ‘representational moderation’.

Thought Structure, Belief Content, and Possession Conditions

According to Peacocke, concepts are individuated by their possession conditions, which are specified in terms of conditions in which certain propositions containing those concepts are believed. In support, Peacocke tries to explain what it is for a thought to have a structure and what it is for a belief to have a propositional content. I show that the possession condition theory cannot answer such fundamental questions. Peacocke’s theory founders because concepts are metaphysically fundamental. They individuate the propositions and thoughts containing them, which in turn individuate the propositional attitudes that are relations to those propositions or thoughts.

Transglobal Evidentialism-Reliabilism

We propose an approach to epistemic justification that incorporates elements of both reliabilism and evidentialism, while also transforming these elements in significant ways. After briefly describing and motivating the non-standard version of reliabilism that Henderson and Horgan call “transglobal” reliabilism, we harness some of Henderson and Horgan’s conceptual machinery to provide a non-reliabilist account of propositional justification (i.e., evidential support). We then invoke this account, together with the notion of a transglobally reliable belief-forming process, to give an account of doxastic justification.

Two-dimensionalism and the “Knowing Which” Requirement

Two-dimensional semantics aims to eliminate the puzzle of necessary a posteriori and contingent a priori truths. Recently many argue that even assuming two-dimensional semantics we are left with the puzzle of necessary and a posteriori propositions. Stephen Yablo (Pacific Philosophical Quarterly, 81, 98–122, 2000) and Penelope Mackie (Analysis, 62(3), 225–236, 2002) argue that a plausible sense of “knowing which” lets us know the object of such a proposition, and yet its necessity is “hidden” and thus a posteriori. This paper answers this objection; I argue that given two-dimensional semantics you cannot know a necessary proposition without knowing that it is true.

On the Coherence of Inversion

In this paper, I shall evaluate a strategy recently used to try to demonstrate the impossibility of behaviorally undetectable spectrum inversion. After showing that the impossibility proof proves too much, I shall identify where it goes wrong. In turn, I shall explain why someone attracted to functionalist and representationalist assumptions might rightly remain agnostic about the possibility of inversion.

Closure,Defeasibility and Conclusive Reasons

It is argued, on the basis of new counterexamples, that neither knowledge nor epistemic justification (or “epistemic rationality”) can reasonably be thought to be closed under logical implication. The argument includes an attempt to reconcile the fundamental intuitions of the opposing parties in the debate.

Equality of Opportunity and Personal Identity

One of the central theses of egalitarian liberals in the domain of distributive justice is that talented individuals should not be allowed to keep their entire market-income even if it flows solely from their greater abilities. This claim is usually supported by one of several arguments or some mixture of them, but in the present paper, I want to concentrate on the version that invokes equality of opportunity as its starting point. Namely, it is claimed that every human being should enjoy an equal starting point in the life-race but that this is not secured insofar as some have greater natural talents than others. Therefore, egalitarians hold that results that arise from such an unfair situation are unjust and should be corrected by a redistributive taxation. I want to criticize this argument by hoping to show that it presupposes an untenable view about identity of persons.