Achille C. Varzi

I focus on three mereological principles: the Extensionality of Parthood (EP), the Uniqueness of Composition (UC), and the Extensionality of Composition (EC). These principles are not equivalent. Nonetheless, they are closely related (and often equated) as they all reflect the basic nominalistic dictum, No difference without a difference maker. And each one of them—individually or collectively—has been challenged on philosophical grounds. In the first part I argue that such challenges do not quite threaten EP insofar as they are either self-defeating or unsupported. In the second part I argue that they hardly undermine the tenability of EC and UC as well.

This volume aims to offer an up-to-date indication of the on-going debate on the nature of logic. The focus is on questions pertaining to the existence and individuation of clear boundaries delineating the concerns of logic: What is their distinctive character? What makes logic a subject of its own, separate from (and generally in the background of) the concerns of other disciplines? What is it for an expression to be a logical constant? Or, perhaps equivalently, what is it for an operation or a relation to be logical? Can these questions be addressed in a general setting, or are they intrinsically unanswerable except within specific frameworks of reference (e.g., a language, or a conceptual scheme)? How are they to be addressed—are they semantic, syntactic, pragmatic? And how do semantics, syntax, or pragmatics contribute to our understanding of these questions? Are the answers fully captured by extant systems of logic? Contributors: E. Bencivenga, J. van Benthem, D. van Dalen, M. García-Carpintero and M. Pérez Otero, A. P. Hazen, A. Koslow, G. Priest, G. Sher.

[ES] Aquí articulo y luego defiendo las dos afirmaciones siguientes: que es un error pensar que la estructura del mundo debe reflejar la estructura de las teorías por las cuales lo representamos, y por medio de las cuales tratamos de descifrarlo, simplemente porque estas teorías parecen funcionar; entre las consecuencias más lamentables de este error está la tendencia generalizada a pensar que debe haber una pluralidad de realidades, o varios niveles diferentes e irreductibles de una realidad estratificada, simplemente porque nuestro credo incluye una pluralidad de teorías cada una de las cuales aparenta ser tan importante y confiable como es irreductible a las demás. [EN] I articulate and then defend the following two claims: it is a mistake to think that the structure of the world should mirror the structure of the theories by which we represent it, and through which we try to decipher it, simply because those theories appear to work; among the most deplorable consequences of this mistake is the widespread tendency to think that there must be a plurality of realities, or several different and irreducible levels of a stratified reality, merely because our credo includes a plurality of theories each of which appears to be as important and trustworthy as it is irreducible to the others.

The idea that an adequate semantics of ordinary language calls for some theory of events has sparked considerable debate among linguists and philosophers. On the one hand, so many linguistic phenomena appear to be explained if (and, according to some authors, only if) we make room for logical forms in which reference to or quantification over events is explicitly featured. Examples include nominalization, adverbial modification, tense and aspect, plurals, and singular causal statements. On the other hand, a number of deep philosophical questions arise as soon as we take events into consideration. Are events entities of a kind? What are their identity and individuation criteria? How does semantic theorizing depend on such metaphysical issues? The aim of this book is to address such issues in some depth, with emphasis precisely on the interplay between linguistic applications and philosophical implications. Contributors: N. Asher, P. M. Bertinetto, J. Brandl, D. Delfitto, R. Eckardt, J. Higginbotham, A. Lenci, T. Parsons, A. ter Meulen, H. Verkuyl. A comprehensive introductory essay (pp. 3-47) is included.

It is shown that a complete axiomatization of classical non-tautologies can be obtained by taking F (falsehood) as the sole axiom along with the two inference rules: (i) if A is a substitution instance of B, then A |– B; and (ii) if A is obtained from B by replacement of equivalent sentences, then A |– B (counting as equivalent the pairs {T, ~F}, {F, F&F}, {F, F&T}, {F, T&F}, {T, T&T}). Since the set of tautologies is also specifiable by purely syntactic means, the resulting picture gives an improved syntactic account of classical sentential logic. The picture can then be completed by considering related systems that prove adequate to specify the set of contradictions, the set of non-contradictions, and the set of contingencies respectively.

A scholarly annotated epic poem on the pitfalls and tribulations of “good philosophizing”. Divided into twenty-eight cantos (in medieval Italian hendecasyllabic terza rima), the poem tells of an allegorical journey through the downward spiral of the philosophers’ hell, where all sorts of thinkers are punished for their faults and mistakes, in the endeavor to reach a way out of the condition of intellectual impasse in which the narrator has found himself. The affinities with Dante’s Inferno are apparent. Whereas Dante’s poem is about human sins and moral felonies, this one is about philosophical errors and fallacies; whereas Virgil takes Dante through the gluttons, the wrathful, the violent, the traitors to parties and countries, etc., here Socrates takes us through the realists, the skeptics, the dualists, the nichilists, the worshipers of language and easy mythos, etc. And yet this is not just a philosophical counterpart of Dante’s masterpiece, even less a parody. We can’t say exactly when, how, and why it was written, but this is an authentic piece of philosophy, a poem of love, a passionate testimony of militant metaphysics. It is the inspired and inspiring journey of someone, anyone, who is truly moved by the Love for Wisdom and by the grueling purification of the intellect that it demands.

We can see mereology as a theory of parthood and topology as a theory of wholeness. How can these be combined to obtain a unified theory of parts and wholes? This paper examines various non-equivalent ways of pursuing this task, with specific reference to its relevance to spatio-temporal reasoning. In particular, three main strategies are compared: (i) mereology and topology as two independent (though mutually related) chapters; (ii) mereology as a general theory subsuming topology; (iii) topology as a general theory subsuming mereology. Some more speculative strategies and directions for further research are also considered.

Like the journal TOPOl, the TOPOl Library is based on the assumption that philosophy is a lively, provocative, delightful activity, which constantly challenges our inherited habits, painstakingly elaborates on how things could be different, in other stories, in counterfactual situations, in alternative possible worlds. Whatever its ideology, whether with the intent of uncovering a truer structure of reality or of shooting our anxiety, of exposing myths or of following them through, the outcome of philosophical activity is always the destabilizing, unsettling generation of doubts, of objections, of criticisms. It follows that this activity is intrinsically a dialogue, that philosophy is first and foremost philosophical discussion, that it requires bringing out conflicting points of view, paying careful, sympathetic attention to their structure, and using this dialectic to articulate one's approach, to make it richer, more thoughtful, more open to variation and play. And it follows that the spirit which one brings to this activity must be one of tolerance, of always suspecting one's own blindness and consequently looking with unbiased eye in every comer, without fearing to pass a (fallible) judgment on what is there but also without failing to show interest and respect.

On the one hand, logic has (or ought to have) nothing to do with metaphysics; it ought to have nothing to do with questions concerning what there is, or whether there is anything at all. On the other hand, metaphysics can hardly get off the ground without the help of logical analysis; to be is to be a truth-maker, and the search for truth-makers requires that we lay open the logical structure of our language. So something’s gotta give: either logical analysis is metaphysically biased, or metaphysicians must make up their mind before resorting to logical analysis. Or both.

In previous work I have argued that talk about negative events should not be taken at face value: typically, what we are inclined to think of as a negative event (John’s failure to go jogging) is just an ordinary, positive event (his going to the movie instead); it is a positive event under a negative description. Here I consider more closely the difficulties that arise in those cases where no positive event seems available to do the job, as with putative cases of causation by omission. In particular, I elaborate on Helen Beebee’s idea that not all causal explanations are reports of causation. When we mention John’s failure to turn off the gas as an explanans of why there was an explosion, we do not say what caused the explosion. We do not mention any of the relevant causes. We just remark that one sort of event that was supposed to occur, and whose occurrence would have prevented the explosion, did not in fact occur.

An overview of the way I picture the amorphous world we live in, built around my comments and responses to nine festschrift essays by A. Borghini (on the Fedro metaphor and the art of butchery), F. Calemi (on the predication principle and metalinguistic nominalism), C. Calosi (on the argument from mereological universalism to extensonality), E. Casetta (on the role of “monsters” in the realism/antirealism debate), V. Giardino (on inductive reasoning, spatial representation, and problem solving), P. Graziani (on mereological notation), P. Pedrini (on the distinction between natural and artificial boundaries), D. Santoro (on causation by omission), and G. Torrengo (on absolute vs. relational space and the problem of incongruent counterparts).

A philosophical exchange broadly inspired by the characters of Berkeley’s Three Dialogues. Hylas is the realist philosopher: the view he stands up for reflects a robust metaphysic that is reassuringly close to common sense, grounded on the twofold persuasion that the world comes structured into entities of various kinds and at various levels and that it is the task of philosophy, if not of science generally, to “bring to light” that structure. Philonous, by contrast, is the anti-realist philosopher (though not necessarily an idealist): his metaphysic is stark, arid, dishearteningly bone-dry, and stems from the conviction that a great deal of the structure that we are used to attribute to the world out there lies, on closer inspection, in our head, in our “organizing practices”, in the complex system of concepts and categories that unrerlie our representation of experience and our need to represent it that way.

What sort of logic do we get if we adopt a supervaluational semantics for vagueness? As it turns out, the answer depends crucially on how the standard notion of validity as truth preservation is recasted. There are several ways of doing that within a supervaluational framework, the main alternative being between “global” construals (e.g., an argument is valid iff it preserves truth-under-all-precisifications) and “local” construals (an argument is valid iff, under all precisifications, it preserves truth). The former alternative is by far more popular, but I argue in favor of the latter, for (i) it does not suffer from a number of serious objections, and (ii) it makes it possible to restore global validity as a defined notion.

Abstract. As a general theory of reasoning—and as a general theory of what holds true under every possible circumstance—logic is supposed to be ontologically neutral. It ought to have nothing to do with questions concerning what there is, or whether there is anything at all. It is for this reason that traditional Aristotelian logic, with its tacit existential presuppositions, was eventually deemed inadequate as a canon of pure logic. And it is for this reason that modern quantification theory, too, with its residue of existentially loaded theorems and patterns of inference, has been claimed to suffer from a defect of logical purity. The law of non-contradiction rules out certain circumstances as impossible—circumstances in which a statement is both true and false, or perhaps circumstances where something both is and is not the case. Is this to be regarded as a further ontological bias?

There are conflicting intuitions concerning the status of a boundary separating two adjacent entities (or two parts of the same entity). The boundary cannot belong to both things, for adjacency excludes overlap; and it cannot belong to neither, for nothing lies between two adjacent things. Yet how can the dilemma be avoided without assigning the boundary to one thing or the other at random? Some philosophers regard this as a reductio of the very notion of a boundary, which should accordingly be treated a mere façon de parler. In this paper I resist this temptation and examine some ways of taking the puzzle at face value within a realist perspective—treating boundaries as ontologically on a par with (albeit parasitic upon) extended parts.

A lot of work in metaphysics relies on linguistic analysis and intuitions. Do we want to know what sort of things there are or could be? Then let’s see what sort of things there must be in order for what we truthfully say to be true. Do we want to see whether x is distinct from y? Then let’s see whether there is any statement that is true of x but not of y. And so on. In this paper I argue that this way of proceeding is full of traps and is bound to be pretty useless unless we already have a good idea of what sort of things there are, and of how we are going to count them.

Some philosophers have gone a long way towards a clarification and a defense of the view that there is genuine (worldly) indeterminacy of identity. Among his reasons for taking this view seriously is the contention that extant formulations of the alternative conception, according to which all indeterminacy lies in the semantics of our language (or in the system of concepts embodied in our language), are not fitted for dealing with a host of identity puzzles. I this paper I take issue with that contention and argue that the semantic conception, if charitably construed, can meet such challenges.