Issue: Issue 12 • Author/s: Angelo Gilio, Giuseppe Sanfilippo
Topics: Epistemology, Metaphysics, Philosophical logic, Philosophy of science
We illustrate the notions of compound and iterated conditionals introduced, in recent papers, as suitable conditional random quantities, in the framework of coherence. We motivate our definitions by examining some concrete examples. Our logical operations among conditional events satisfy the basic probabilistic properties valid for unconditional events. We show that some, intuitively acceptable, compound sentences on conditionals can be analyzed in a rigorous way in terms of suitable iterated conditionals. We discuss the Import-Export principle, which is not valid in our approach, by also examining the inference from a material…
Issue: Issue 12 • Author/s: Jean Baratgin
Topics: Epistemology, Metaphysics, Philosophical logic, Philosophy of science
The trivalent and functional theory of the truth of conditionals developed by Bruno de Finetti has recently gathered renewed interests, particularly from philosophical logic, psychology and linguistics. It is generally accepted that de Finetti introduced his theory in 1935. However, a reading of his first publications indicates an earlier conception of almost all his theory. We bring to light a manuscript and unknown writings, dating back to 1928 and 1932, detailing de Finetti’s theory. The two concepts of thesis and hypothesis are presented as a cornerstone on which logical connectives…
Issue: Issue 12 • Author/s: Alberto Mura
Topics: Epistemology, Metaphysics, Philosophical logic, Philosophy of language
According to Lewis’ Triviality Results (LTR), conditionals cannot satisfy the equation (E) P(C if A) = P(C | A), except in trivial cases. Ernst Adams (1975), however, provided a probabilistic semantics for the so-called simple conditionals that also satisfies equation (E) and provides a probabilistic counterpart of logical consequence (called p-entailment). Adams’ probabilistic semantics is coextensive to Stalnaker-Thomason’s (1970) and Lewis’ (1973) semantics as far as simple conditionals are concerned. A theorem, proved in McGee 1981, shows that no truth-functional many-valued logic allows a relation of logical consequence coextensive with…
Issue: Issue 14 • Author/s: Tom Donaldson, Jennifer Wang
Topics: Epistemology, Metaphysics, Modal Logic, Ontology
In the middle of the last century, it was common to explain the notion of necessity in linguistic terms. A necessary truth, it was said, is a sentence whose truth is guaranteed by linguistic rules. Quine famously argued that, on this view, de re modal claims do not make sense. “Porcupettes are porcupines” is necessarily true, but it would be a mistake to say of a particular porcupette that it is necessarily a porcupine, or that it is possibly purple. Linguistic theories of necessity fell out of favour with the…
Issue: Issue 14 • Author/s: Alastair Wilson
Topics: Epistemology, Metaphysics, Modal Logic, Ontology
My topic in this paper is the relationships of metaphysical priority which might hold between the different alethic modal statuses—necessity, contingency, possibility and impossibility. In particular, I am interested in exploring the view that the necessity of necessities is ungrounded while the contingency of contingencies is grounded—a scenario I call ‘necessity first’. I will explicate and scrutinize the contrast between necessity first and its ‘contingency first’ contrary, and then compare both views with ‘multimodal’ and ‘amodal’ alternatives, drawing on David Lewis’s modal realism and Barbara Vetter’s potentialism as example cases.…
Issue: Issue 14 • Author/s: Nathan Wildman
Topics: Epistemology, Metaphysics, Modal Logic, Ontology
General consensus has it that contingencies lack the requisite modal umph to serve as explanations for the modal status of necessities. The central aim of this paper is to show that this received opinion is incorrect: contingent necessity-makers are in fact possible. To do so, I identify certain conditions the satisfaction of which entail the possibility of contingent necessity-makers. I then argue for two broad instances where these conditions are satisfied. Consequently, the associated necessities in fact have contingent necessity-makers.
Issue: Issue 14 • Author/s: James L.D. Brown
Topics: Epistemology, Metaphysics, Modal Logic, Ontology
This paper asks whether a necessity can be the source of necessity. According to an influential argument due to Simon Blackburn, it cannot. This paper argues that although Blackburn fails to show that a necessity cannot be the source of necessity, extant accounts fail to establish that it is, with particular focus on Bob Hale’s essentialist theory and Christopher Peacocke’s ‘principle-based’ theory of modality. However, the paper makes some positive suggestions for what a satisfactory answer to the challenge must look like.
Issue: Issue 14 • Author/s: William Bondi Knowles
Topics: Epistemology, Metaphysics, Modal Logic, Ontology
Blackburn’s dilemma (as commonly understood) is that in explaining truths of the form ‘Necessarily-P’ we have to appeal either to a necessary truth, in which case we don’t seem to make the right kind of progress, or to a contingent truth, in which case we seem to undermine the necessity we were meant to be explaining. This paper advances two claims. First, it is argued that the dilemma is wider in scope than usually supposed. The standard assumption (evident also in Blackburn’s original paper (1993)) is that the dilemma applies…
Issue: Issue 14 • Author/s: Simon Babbs, Joshua Mendelsohn
Topics: Epistemology, Metaphysics, Modal Logic, Ontology
What does it take for a necessity operator to capture an absolute as opposed to merely relative sense of necessity? Bob Hale (2013) delineates and formalizes three conceptions of absolute necessity, which he takes to be co-extensive, and to permit non-logical, absolutely necessary truths. We raise problems with Hale’s three conceptions of absolute necessity, both on their own terms and as regards the compatibility of all the features Hale wants them to possess. We show that Hale’s formulations are less informative than they may seem. They are all in important…