Ontology engineering is a hard and error-prone task, in which small changes may lead to errors, or even produce an inconsistent ontology. As ontologies grow in size, the need for automated methods for repairing inconsistencies while preserving as much of the original knowledge as possible increases. Most previous approaches to this task are based on removing a few axioms from the ontology to regain consistency. We propose a new method based on weakening these axioms to make them less restrictive, employing (...) the use of refinement operators. We introduce the theoretical framework for weakening DL ontologies, propose algorithms to repair ontologies based on the framework, and provide an analysis of the computational complexity. Through an empirical analysis made over real-life ontologies, we show that our approach preserves significantly more of the original knowledge of the ontology than removing axioms. (shrink)

We discuss the role of perceptron (or threshold) connectives in the context of Description Logic, and in particular their possible use as a bridge between statistical learning of models from data and logical reasoning over knowledge bases. We prove that such connectives can be added to the language of most forms of Description Logic without increasing the complexity of the corresponding inference problem. We show, with a practical example over the Gene Ontology, how even simple instances of perceptron connectives are (...) expressive enough to represent learned, complex concepts derived from real use cases. This opens up the possibility to import concepts learnt from data into existing ontologies. (shrink)

The properties of the ${\forall^{1}}$ quantifier defined by Kontinen and Väänänen in [13] are studied, and its definition is generalized to that of a family of quantifiers ${\forall^{n}}$ . Furthermore, some epistemic operators δ n for Dependence Logic are also introduced, and the relationship between these ${\forall^{n}}$ quantifiers and the δ n operators are investigated.The Game Theoretic Semantics for Dependence Logic and the corresponding Ehrenfeucht- Fraissé game are then adapted to these new connectives.Finally, it is proved that the ${\forall^{1}}$ quantifier (...) is not uniformly definable in Dependence Logic, thus answering a question posed by Kontinen and Väänänen in the above mentioned paper. (shrink)

We develop a semantics for independence logic with respect to what we will call general models. We then introduce a simpler entailment semantics for the same logic, and we reduce the validity problem in the former to the validity problem in the latter. Then we build a proof system for independence logic and prove its soundness and completeness with respect to entailment semantics.

We examine the transitions between sets of possible worlds described by the compositional semantics of Modal Dependence Logic, and we use them as the basis for a dynamic version of this logic. We give a game theoretic semantics, a (compositional) transition semantics and a power game semantics for this new variant of modal Dependence Logic, and we prove their equivalence; and furthermore, we examine a few of the properties of this formalism and show that Modal Dependence Logic can be recovered (...) from it by reasoning in terms of reachability. Then we show how we can generalize this approach to a very general formalism for reasoning about transformations between pointed Kripke models. (shrink)

We present a compositional semantics for first-order logic with imperfect information that is equivalent to Sevenster and Sandu’s equilibrium semantics (under which the truth value of a sentence in a finite model is equal to the minimax value of its semantic game). Our semantics is a generalization of an earlier semantics developed by the first author that was based on behavioral strategies, rather than mixed strategies.

In Team Semantics, a dependency notion is strongly first order if every sentence of the logic obtained by adding the corresponding atoms to First-Order Logic is equivalent to some first-order sentence. In this work it is shown that all nontrivial dependency atoms that are strongly first order, downwards closed, and relativizable are definable in terms of constancy atoms.Additionally, it is shown that any strongly first-order dependency is safe for any family of downwards closed dependencies, in the sense that every sentence (...) of the logic obtained by adding to First-Order Logic both the strongly first-order dependency and the downwards closed dependencies is equivalent to some sentence of the logic obtained by adding only the downwards closed dependencies. (shrink)

We introduce and discuss a knowledge-driven distillation approach to explaining black-box models by means of two kinds of interpretable models. The first is perceptron (or threshold) connectives, which enrich knowledge representation languages such as Description Logics with linear operators that serve as a bridge between statistical learning and logical reasoning. The second is Trepan Reloaded, an ap- proach that builds post-hoc explanations of black-box classifiers in the form of decision trees enhanced by domain knowledge. Our aim is, firstly, to target (...) a model-agnostic distillation approach exemplified with these two frameworks, secondly, to study how these two frameworks interact on a theoretical level, and, thirdly, to investigate use-cases in ML and AI in a comparative manner. Specifically, we envision that user-studies will help determine human understandability of explanations generated using these two frameworks. (shrink)

Axiom weakening is a technique that allows for a fine-grained repair of inconsistent ontologies. Its main advantage is that it repairs on- tologies by making axioms less restrictive rather than by deleting them, employing the use of refinement operators. In this paper, we build on pre- viously introduced axiom weakening for ALC, and make it much more irresistible by extending its definitions to deal with SROIQ, the expressive and decidable description logic underlying OWL 2 DL. We extend the definitions of (...) refinement operator to deal with SROIQ constructs, in particular with role hierarchies, cardinality constraints and nominals, and illustrate its application. Finally, we discuss the problem of termi- nation of an iterated weakening procedure. (shrink)

When people combine concepts these are often characterised as “hybrid”, “impossible”, or “humorous”. However, when simply considering them in terms of extensional logic, the novel concepts understood as a conjunctive concept will often lack meaning having an empty extension (consider “a tooth that is a chair”, “a pet flower”, etc.). Still, people use different strategies to produce new non-empty concepts: additive or integrative combination of features, alignment of features, instantiation, etc. All these strategies involve the ability to deal with conflicting (...) attributes and the creation of new (combinations of) properties. We here consider in particular the case where a Head concept has superior ‘asymmetric’ control over steering the resulting concept combination (or hybridisation) with a Modifier concept. Specifically, we propose a dialogical approach to concept combination and discuss an implementation based on axiom weakening, which models the cognitive and logical mechanics of this asymmetric form of hybridisation. (shrink)

Axiom weakening is a novel technique that allows for fine-grained repair of inconsistent ontologies. In a multi-agent setting, integrating ontologies corresponding to multiple agents may lead to inconsistencies. Such inconsistencies can be resolved after the integrated ontology has been built, or their generation can be prevented during ontology generation. We implement and compare these two approaches. First, we study how to repair an inconsistent ontology resulting from a voting-based aggregation of views of heterogeneous agents. Second, we prevent the generation of (...) inconsistencies by letting the agents engage in a turn-based rational protocol about the axioms to be added to the integrated ontology. We instantiate the two approaches using real-world ontologies and compare them by measuring the levels of satisfaction of the agents w.r.t. the ontology obtained by the two procedures. (shrink)

We introduce a family of operators to combine Description Logic concepts. They aim to characterise complex concepts that apply to instances that satisfy \enough" of the concept descriptions given. For instance, an individual might not have any tusks, but still be considered an elephant. To formalise the meaning of "enough", the operators take a list of weighted concepts as arguments, and a certain threshold to be met. We commence a study of the formal properties of these operators, and study some (...) variations. The intended applications concern the representation of cognitive aspects of classi cation tasks: the interdependencies among the attributes that de ne a concept, the prototype of a concept, and the typicality of the instances. (shrink)

Ontologies represent principled, formalised descriptions of agents’ conceptualisations of a domain. For a community of agents, these descriptions may differ among agents. We propose an aggregative view of the integration of ontologies based on Judgement Aggregation (JA). Agents may vote on statements of the ontologies, and we aim at constructing a collective, integrated ontology, that reflects the individual conceptualisations as much as possible. As several results in JA show, many attractive and widely used aggregation procedures are prone to return inconsistent (...) collective ontologies. We propose to solve the possible inconsistencies in the collective ontology by applying suitable weakenings of axioms that cause inconsistencies. (shrink)

In this paper I deal with Nietzsche's theory of knowledge in the context of 19th century epistemology. In particular, I argue that, even though Nietzsche shows the ontological lack of content of truths (both on the theoretic and on the moral plane), he nevertheless leaves the space for a practical use of them, in a way that can be compared with William James' pragmatism. I thus deal with Nietzsche's and James' concept of "truth", and show their relationship with some outcomes (...) of Ernst Mach's epistemology. (shrink)

During his late period, Nietzsche is particularly concerned with the value that mankind attributes to truth. In dealing with that topic, Nietzsche is not primarly interested in the metaphysical disputes on truth, but rather in the effects that the "will to truth" has on the human being. In fact, he argues that the "faith in a value as such of truth" influenced Western culture and started the anthropological degeneration of the human type that characterizes European morality. To call into question (...) the value of truth is therefore necessary, if one wants to help mankind to find her way in the labyrinth of nihilism. -/- In this new addition to Nietzsche scholarship, Gori explores the origin and aim of the philosopher's late perspectival thought by merging the theoretical with the historical approach, with a special focus on the epistemological debate that influenced Nietzsche. As a result, the book provides a contextual reading of the issue that supports the idea that Nietzsche’s attitude in addressing the problem of truth is, in a broad sense, pragmatic. (shrink)

Léon Brunschvicg's contribution to philosophical thought in fin-de-siècle France receives full explication in the first English-language study on his work. Arguing that Brunschvicg is crucial to understanding the philosophical schools which took root in 20th-century France, Pietro Terzi locates Brunschvicg alongside his contemporary Henri Bergson, as well as the range of thinkers he taught and influenced, including Lévinas, Merleau-Ponty, de Beauvoir, and Sartre. Brunschvicg's deep engagement with debates concerning spiritualism and rationalism, neo-Kantian philosophy, and the role of mathematics in (...) philosophy made him the perfect supervisor for a whole host of nascent philosophical ideas which were forming in the work of his students. Terzi outlines Brunchvicg's defence of neo-Kantian judgement, historical analysis and the inextricability of the natural and humanist sciences to any rigorous system of philosophy, with wide-ranging implications for contemporary scholarship. (shrink)

This chapter explores Nietzsche’s and Wittgenstein’s views on language and knowledge, establishing a philosophical dialogue between two different positions, which are based on a similar anti-essentialist and instrumentalist concern. The chapter will first focus on Nietzsche’s conception of language as the expression of valuational perspectives developing through the natural and cultural history of mankind. It will then consider Wittgenstein’s account of language as the inherited background of our practical engagement with the world. Finally, by bringing Nietzsche’s and Wittgenstein’s views together, (...) the last section reflects on the crucial strategic move they make in their respective battle against the bewitchment of our intelligence by means of language. -/- . (shrink)

The chapter explores comparatively the attention to the practical dimension that—each in his own way—Michel Foucault, Friedrich Nietzsche, and the classic pragmatist thinker William James pay when confronted with the challenge of providing a non-skeptical response to the relativist stance on truth that arose in the post-Kantian age. Particular focus will be given to the extent to which these three authors conceived of the practical framework as the only one that allows us to meaningfully address and determine truth.

I. Del regno terreno.--II. Del regno celeste.--III. Del regno papale.

Reciprocal libertarianism is a version of left-wing libertarianism that combines self-ownership with an egalitarian distribution of resources according to reciprocity. In this paper, I show that reciprocal libertarianism is a coherent and appealing view. I discuss how reciprocal libertarians can handle conflicts between self-ownership and reciprocity, and I show that reciprocal libertarianism can be realised in a framework of individual ownership of external resources or in a socialist scheme of common ownership (libertarian socialism). I also compare reciprocal libertarianism with left-libertarian (...) approaches: I argue that a reciprocity-sensitive version of left-libertarianism (reciprocal left-libertarianism) is coherent and morally superior to traditional left-libertarianism, on grounds of incorporating a distinctively solidaristic and recognition-oriented aspect of equality. The policy implications of reciprocal libertarianism will differ depending on which rights people can have over external resources, but all reciprocal libertarian views acknowledge the existence of social rights that people have as co-operators. (shrink)

Wilfrid Sellars’ denunciation of the Myth of the Given was meant to clarify, against empiricism, that perceptual episodes alone are insufficient to ground and justify perceptual knowledge. Sellars showed that in order to accomplish such epistemic tasks, more resources and capacities, such as those involved in using concepts, are needed. Perceptual knowledge belongs to the space of reasons and not to an independent realm of experience. Dan Hutto and Eric Myin have recently presented the Hard Problem of Content as an (...) ensemble of reasons against naturalistic accounts of content. In a nutshell, it states that covariance relations—even though they are naturalistically acceptable explanatory resources—do not constitute content. The authors exploit this move in order to promote their preferred radical enactivist and anti-representationalist option, according to which, basic minds—the lower stratum of cognition—do not involve content. Although it is controversial to argue that the Hard Problem of Content effectively dismisses naturalistic theories of representation, a central aspect of it—the idea that information as covariance does not suffice to explain content—finds support among the defenders of classical cognitive representationalism, such as Marcin Miłkowski. This support—together with the acknowledgment this remark about covariance is a point already made by Sellars in his criticism of the Myth of the Given—has a number of interesting implications. Not only is it of interest for the debates about representationalism in cognitive science, where it can be understood as an anticipatory move, but it also offers some clues and insights for reconsidering some issues along Sellarsian lines—a conflation between two concepts of representation that is often assumed in cognitive science, a distinction between two types of relevant normativities, and a reconsideration of the naturalism involved in such explanations. (shrink)

Note biografiche -- Opere filosofiche theologiche e varie -- Le questioni I-V del De "conscientia" in relazione alle fonti.

Léon Brunschvicg's contribution to philosophical thought in fin-de-siècle France receives full explication in the first English-language study on his work. Arguing that Brunschvicg is crucial to understanding the philosophical schools which took root in 20th-century France, Pietro Terzi locates Brunschvicg alongside his contemporary Henri Bergson, as well as the range of thinkers he taught and influenced, including Lévinas, Merleau-Ponty, de Beauvoir, and Sartre. Brunschvicg's deep engagement with debates concerning spiritualism and rationalism, neo-Kantian philosophy, and the role of mathematics in (...) philosophy made him the perfect supervisor for a whole host of nascent philosophical ideas which were forming in the work of his students. Terzi outlines Brunchvicg's defence of neo-Kantian judgement, historical analysis and the inextricability of the natural and humanist sciences to any rigorous system of philosophy, with wide-ranging implications for contemporary scholarship. (shrink)

The paper explores the issue of moral relativism in Nietzsche, and tries to argue that Nietzsche's attitude towards moral values does not support a radical relativism according to which since (i) every moral interpretation is relative to a judging perspective, and (ii) an absolute viewpoint is lacking, then (iii) every moral interpretation seems to be as true, valid or justified as the others. On the contrary, Nietzsche's perspectivism leaves space for a rank order among values, whose establishment is considered by (...) Nietzsche as the future task of the philosopher. (shrink)