In the TACITUS project for using commonsense knowledge in the understanding of texts about mechanical devices and their failures, we have been developing various commonsense theories that are needed to mediate between the way we talk about the behavior of such devices and causal models of their operation. Of central importance in this effort is the axiomatization of what might be called commonsense metaphysics. This includes a number of areas that figure in virtually every domain of discourse, such as granularity, (...) scales, time, space, material, physical objects, shape, causality, functionality, and force. Our effort has been to construct core theories of each of these areas, and then to define, or at least characterize, a large number of lexical items in terms provided by the core theories. In this paper we discuss our methodological principles and describe the key ideas in the various domains we are investigating. (shrink)

There seem to be many kinds of moral duties. We should keep our promises; we should pay our debts of gratitude; we should compensate those we’ve wronged; we should avoid doing or intending harm; we should help those in need. These constitute, some worry, an unconnected heap of duties: the realm of commonsense morality is a disorganized mess. In this paper, we outline a strategy for unifying commonsense moral duties. We argue that they can be understood in terms of contact (...) with value. You are in contact with a value when you are manifest in it or when it is manifest in you. You have reason to get in contact with the good and avoid contact with evil. And when you’re in contact with a value, the weight of the reasons it grounds are amplified for you. These ideas, we argue, can bring order to the chaos of commonsense morality. (shrink)

This paper challenges Mäki's argument about commonsensibles by offering a case study from contemporary microeconomics – contemporary revealed preference theory (hereafter CRPT) – where terms like "preference," "utility," and to some extent "choice," are radical departures from the common sense meanings of these terms. Although the argument challenges the claim that economics is inhabited solely by commonsensibles, it is not inconsistent with such folk notions being common in economic theory.

Analytic philosophy has transgender trouble. In this paper, I explore potential explanations for this trouble, focusing on the notion of 'cisgender commonsense' and its place in philosophical methodology.

Commonsense reasoning is a crucial human ability employed in everyday tasks. In this talk I provide a knowledge level analysis of the main representational and reasoning problems affecting the cognitive architectures for what concerns this issue. In providing this analysis I will show, by considering some of the main cognitive architectures currently available (e.g. SOAR, ACT-R, CLARION), how one of the main problems of such architectures is represented by the fact that their knowledge representation and processing mechanisms are not sufficiently (...) constrained with insights coming from cognitive science (Lieto 2021; Lieto, Lebiere, Oltramari, 2018). As a possible way out to such knowledge processing issues, I present the main assumptions that have led to the development of the Dual PECCS categorization system (Lieto, Radicioni, Rho 2017) and discuss some of the lessons learned and their possible implications in the design of the knowledge modules and knowledge-processing mechanisms of integrated cognitive architectures. (shrink)

Some research suggests that moral behavior can be strongly influenced by trivial features of the environment of which we are completely unaware. Philosophers, psychologists, and neuroscientists have argued that these findings undermine our commonsense notions of agency and responsibility, both of which emphasize the role of practical reasoning and conscious deliberation in action. We present the results of four vignette-based studies (N = 1,437) designed to investigate how people think about the metaphysical and moral implications of scientific findings that reveal (...) our susceptibility to automaticity and situational influences. When presented with lightly fictionalized narratives about these findings, participants exhibit no tendency toward changing judgments of freedom and responsibility compared to control groups. This suggests that people seem unwilling to adopt skeptical attitudes about agency on the basis of these scientific findings. (shrink)

Abstract The purpose of this paper is twofold: (i) we will argue that formal semantics might have faltered due to its failure in distinguishing between two fundamentally very different types of concepts, namely ontological concepts, that should be types in a strongly-typed ontology, and logical concepts, that are predicates corresponding to properties of, and relations between, objects of various ontological types; and (ii) we show that accounting for these differences amounts to a new formal semantics; one that integrates lexical and (...) compositional semantics in one coherent framework and one where formal semantics is embedded with a strongly typed ontology; an ontology that reflects our commonsense knowledge of the world and the way we talk about it in ordinary language. We will show how in such a framework a number of challenges in the semantics of natural language are adequately and systematically treated. (shrink)

Trent Dougherty argues (contra Jonathan Matheson) that when taking into consideration the probabilities involving skeptical theism (ST) and gratuitous evils, an agent may reasonably affirm both ST and that gratuitous evils exist. In other words, Dougherty thinks that assigning a greater than .5 probability to ST is insufficient to defeat the commonsense problem of evil. I argue that Dougherty’s response assumes, incorrectly, that ST functions solely as an evidential defeater, and that, when understood as a closure of inquiry defeater, ST (...) may still defeat reasonable belief in gratuitous evils, even in the face of strong evidence that gratuitous evils exist. (shrink)

We argue that logical semantics might have faltered due to its failure in distinguishing between two fundamentally very different types of concepts: ontological concepts, that should be types in a strongly-typed ontology, and logical concepts, that are predicates corresponding to properties of and relations between objects of various ontological types. We will then show that accounting for these differences amounts to the integration of lexical and compositional semantics in one coherent framework, and to an embedding in our logical semantics of (...) a strongly-typed ontology that reflects our commonsense view of the world and the way we talk about it in ordinary language. We will show that in such a framework a number of challenges in natural language semantics can be adequately and systematically treated. (shrink)

We describe an experimental approach toward implementing a commonsense "microtheory" for buying and selling. Our prototype system characterizes how intelligent agents hold items and money, how they buy and sell items, and the way money and items are transferred. The ontology of the system includes money (cash, check, credit card), agents (people, organizations), items (movable, real estate, service), barter, and the notions of transfer, loan, buying by installments, profit, and loss.

Inventing novel knowledge to solve problems is a crucial, creative, mechanism employed by humans, to extend their range of action. In this talk, I will show how commonsense reasoning plays a crucial role in this respect. In particular, I will present a cognitively inspired reasoning framework for knowledge invention and creative problem solving exploiting TCL: a non-monotonic extension of a Description Logic (DL) of typicality able to combine prototypical (commonsense) descriptions of concepts in a human-like fashion. The proposed approach has (...) been tested both in the task of goal-driven concept invention and has additionally applied within the context of serendipity-based recommendation systems. I will present the obtained results, the lessons learned, and the road ahead of this research path. (shrink)

Fifty years of effort in artificial intelligence (AI) and the formalization of legal reasoning have produced both successes and failures. Considerable success in organizing and displaying evidence and its interrelationships has been accompanied by failure to achieve the original ambition of AI as applied to law: fully automated legal decision-making. The obstacles to formalizing legal reasoning have proved to be the same ones that make the formalization of commonsense reasoning so difficult, and are most evident where legal reasoning has to (...) meld with the vast web of ordinary human knowledge of the world. Underlying many of the problems is the mismatch between the discreteness of symbol manipulation and the continuous nature of imprecise natural language, of degrees of similarity and analogy, and of probabilities. (shrink)

Trent Dougherty has argued that commonsense epistemology and skeptical theism are incompatible. In this paper, I explicate Dougherty’s argument, and show that (at least) one popular form of skeptical theism is compatible with commonsense epistemology.

The success of set theory as a foundation for mathematics inspires its use in artificial intelligence, particularly in commonsense reasoning. In this survey, we briefly review classical set theory from an AI perspective, and then consider alternative set theories. Desirable properties of a possible commonsense set theory are investigated, treating different aspects like cumulative hierarchy, self-reference, cardinality, etc. Assorted examples from the ground-breaking research on the subject are also given.

Commonsense reasoning is one of the main open problems in the field of Artificial Intelligence (AI) while, on the other hand, seems to be a very intuitive and default reasoning mode in humans and other animals. In this talk, we discuss the different paradigms that have been developed in AI and Computational Cognitive Science to deal with this problem (ranging from logic-based methods, to diagrammatic-based ones). In particular, we discuss - via two different case studies concerning commonsense categorization and knowledge (...) invention tasks - how cognitively inspired heuristics can help (both in terms of efficiency and efficacy) in the realization of intelligent artificial systems able to reason in a human-like fashion, with results comparable to human-level performances. (shrink)

In this dissertation, I argue that commonsense morality is best understood as an agent-relative consequentialist theory, that is, as a theory according to which agents ought always to bring about what is, from their own individual perspective, the best available state of affairs. I argue that the agent-relative consequentialist can provide the most plausible explanation for why it is wrong to commit a rights violation even in order to prevent a number of other agents from committing comparable rights violations: agents (...) bear a special responsibility for their own actions and consequently a state of affairs where an agent has herself committed a rights violation is worse, from her perspective, than a state of affairs where a number of other agents have committed comparable rights violations. I also argue that agent-relative consequentialism can accommodate moral options despite being a theory which requires agents always to do the best they can. (shrink)

This paper proposes a methodological strategy to investigate the question of the individuation of the senses both from a commonsensical and a scientific point of view. We start by discussing some traditional and recent criteria for distinguishing the senses and argue that none of them taken in isolation seems to be able to handle both points of views. We then pay close attention to the faculty of hearing which offers promising examples of the strategy we pursue of combining commonsense and (...) science. In particular, we argue in favour of a distinction between two kinds of modes of presentation associated with sound perception: a mechanical mode of presentation that makes sounds perceptible by other modalities than audition such as touch and a tonal mode of presentation that makes people conceive of sounds as the proper objects of auditory perception. (shrink)

Reasoning over our knowledge bases and theories often requires non-deductive inferences, especially – but by no means only – when commonsense reasoning is the case, i.e. when practical agency is called for. This kind of reasoning can be adequately formalized via the notion of supraclassical consequence, a non-deductive consequence tightly associated with default and non-monotonic reasoning and featuring centrally in abductive, inductive, and probabilistic logical systems. In this paper, we analyze core concepts and problems of these systems in the light (...) of supraclassical consequence. (shrink)

I will review the main problems concerning commonsense reasoning in machines and I will present resent two different applications - namaly: the Dual PECCS linguistic categorization system and the TCL reasoning framework that have been developed to address, respectively, the problem of typicality effects and the one of commonsense compositionality, in a way that is integrated or compliant with different cognitive architectures thus extending their knowledge processing capabilities In doing so I will show how such aspects are better dealt with (...) at different levels of representation and will discuss how the adoption of a cognitively inspired approach be useful in the design and implementation of the next generation AI systems mastering commonsense. (shrink)

The special composition question is the question, ‘When do some things compose something?’ The answers to this question in the literature have largely been at odds with common sense, either by allowing that any two things compose something, or by denying the existence of most ordinary composite objects. I propose a new ‘series-style’ answer to the special composition question that accords much more closely with common sense, and I defend this answer from van Inwagen's objections. Specifically, I will argue that (...) the proposed answer entails the transitivity of parthood, that it is non-circular, and that it casts some light on the ancient puzzle about the Ship of Theseus. (shrink)

The established two tracks of neuroenhancement, moral and cognitive enhancements, rest on the characterization of commonsense morality as a set of static psychological dispositions. In this paper, I challenge this way of describing commonsense morality. I draw a parallel between commonsense psychology and commonsense morality, and I propose that the right way to characterize commonsense morality is as an empirically evaluable theory, with a structure similar to a scientific theory. I argue further that psychological dispositions to react in certain ways (...) require the tacit endorsement of a commonsense moral theory. By adopting this view, I argue that the way to change our psychological dispositions is by changing the background theory that produces them. I conclude that when commonsense morality is construed as an empirically evaluable theory, the cleft between the abilities that support scientific progress and the abilities that promote moral progress closes and it becomes evident that the way to promote both types of advancements is through cognitive enhancement. (shrink)

Dynamic conceptual reframing represents a crucial mechanism employed by humans, and partially by other animal species, to generate novel knowledge used to solve complex goals. In this talk, I will present a reasoning framework for knowledge invention and creative problem solving exploiting TCL: a non-monotonic extension of a Description Logic (DL) of typicality able to combine prototypical (commonsense) descriptions of concepts in a human-like fashion [1]. The proposed approach has been tested both in the task of goal-driven concept invention [2,3] (...) and has additionally applied within the context of serendipity-based recommendation systems [4]. I will present the obtained results, the lessons learned, and the road ahead of this research path. -/- . (shrink)

For a symposium on Douglas W. Portmore's Commonsense Consequentialism: Wherein Morality Meets Rationality.

In this work we present an explainable system for emotion attribution and recommendation (called DEGARI (Dynamic Emotion Generator And ReclassIfier) relying on a recently introduced probabilistic commonsense reasoning framework (i.e. the TCL logic, see Lieto & Pozzato 2020) which is based on a human-like procedure for the automatic generation of novel concepts in a Description Logics knowledge base (see also Lieto et al. 2019, Chiodino et al. 2020 for other applications). In particular, in order to model human-like forms of concept (...) combinations, the TCL logic combines a probabilistic description logics of typicality with the HEAD-MODIFIER heuristics coming from cognitive semantics. In the context of our application of such framework, our system exploits the logic TCL to automatically generate novel commonsense semantic representations of compound emotions (e.g. Love as derived from the combination of Joy and Trust according to Plutchik’s theory of emotions, see Plutchik 2001). The generated emotions corresponds to prototypes, i.e. commonsense representations of given concepts, and have been used to reclassify emotion-related contents in a variety of artistic domains. We have tested our system in the context of the H2020 EU project SPICE for providing artistic recommendations of museum items in the Galleria di Arte Moderna (GAM) of Turin. The obtained results (reported in Lieto et al, 2021 and Lieto at al., to appear) show promising results for what concerns both the acceptance of the provided affective recommendation and the explainability associated to each suggestion made by the users. Here we discuss, the open problems and the lessons learned. -/- . (shrink)

I will present two different applications - Dual PECCS and the TCL reasoning framework - addressing some crucial aspects of commonsense reasoning (namely: dealing with typicality effects and with the problem of commonsense compositionality) in a way that is integrated or compliant with different cognitive architectures. In doing so I will show how such aspects are better dealt with at different levels of representation and will discuss the adopted solution to integrate such representational layers.

We propose a nonmonotonic Description Logic of typicality able to account for the phenomenon of the combination of prototypical concepts. The proposed logic relies on the logic of typicality ALC + TR, whose semantics is based on the notion of rational closure, as well as on the distributed semantics of probabilistic Description Logics, and is equipped with a cognitive heuristic used by humans for concept composition. We first extend the logic of typicality ALC + TR by typicality inclusions of the (...) form p :: T(C) v D, whose intuitive meaning is that “we believe with degree p about the fact that typical Cs are Ds”. As in the distributed semantics, we define different scenarios containing only some typicality inclusions, each one having a suitable probability. We then exploit such scenarios in order to ascribe typical properties to a concept C obtained as the combination of two prototypical concepts. We also show that reasoning in the proposed Description Logic is EXPTIME-complete as for the underlying standard Description Logic ALC. (shrink)

I accomplish two things in this paper. I explain the motivation for including experimental research in philosophical projects on epistemic reasons and the basing relation. And I present the first experimental contributions to these projects. The results from two experiments advance our understanding of the ordinary concepts of reasons and basing and set the stage for further research on the topics. More specifically, the results support a causal theory of the basing relation, according to which reasons are causes, and a (...) dualist theory of epistemic reasons, according to which reasons include both psychological and non-psychological items. (shrink)

According to Agnosticism with a capital A, even if we don’t see how any reason we know of would justify God in permitting all the evil in the world and even if we lack evidential and non-evidential warrant for theism, we should not infer that there probably is no reason that would justify God. That’s because, under those conditions, we should be in doubt about whether the goods we know of constitute a representative sample of all the goods there are, (...) among relevantly similar things. In my "Epistemic Humility, Arguments from Evil, and Moral Skepticism" (2009), I defended Agnosticism against the charge that it leaves us in doubt about whether we are obligated to intervene to prevent horrific suffering we can prevent at no risk to ourselves. In his “Agnosticism, Skeptical Theism, and Moral Obligation” (2014), Stephen Maitzen argues that, in light of my defense, Agnosticism is at odds with commonsense morality’s insistence that we have an obligation to intervene in such cases. In the present essay, I argue that the moral principle Maitzen seems to impute to commonsense (it's hard to tell what principle he has in mind) is false and that a moral principle much more in keeping with commonsense is compatible with Agnosticism and my defense of it. Along the way, I mention multiple misrepresentations Maitzen makes of Agnosticism and my defense of it. (shrink)

This work describes an explainable system for emotion attribution and recommendation (called DEGARI (Dynamic Emotion Generator And ReclassIfier) relying on a recently introduced probabilistic commonsense reasoning framework.

Invited Lecture at the SRM ACM Student Chapter, India, on Cognitive Heuristics for Commonsense Thinking and Reasoning in the next generation Artificial Intelligence. The lecture proposes a historical and technical overview of strategies for commonsense reasoning in AI.

This paper investigates an alternative set theory (due to Peter Aczel) called Hyperset Theory. Aczel uses a graphical representation for sets and thereby allows the representation of non-well-founded sets. A program, called HYPERSOLVER, which can solve systems of equations defined in terms of sets in the universe of this new theory is presented. This may be a useful tool for commonsense reasoning.

In his 2013 book, “Moral Tribes: Emotion, Reason, and the Gap between Us and Them,” Joshua Greene1 contemplates two tragedies. The first is the tragedy of the commons, a well- studied problem in the game theory and psychology literature. Here, if people are truly self- interested, cooperation cannot arise, and everyone will use the commons until it is depleted. This problem is succinctly called the “Me vs. Us” problem. The second is the tragedy of the commonsense morality, which Greene named, (...) refers to the problem of cooperation among groups, the “Us vs. Them” problem. (shrink)

Our commonsense understanding of meaning and motive is realized via the semantic encoding of causal role. Appreciating this together with other features of semantic theories enables us to see that methodological critiques of psychoanalysis, such as those by Popper and Grunbaum, systematically fail to take account of empirical data, and if taken seriously would render commonsense understanding of mind and language void. This is particularly problematic if we consider much of what we regard ourselves as knowing is registered in language, (...) or understood through our use of it, since this includes science itself. (shrink)

In this paper we present a framework for the dynamic and automatic generation of novel knowledge obtained through a process of commonsense reasoning based on typicality-based concept combination. We exploit a recently introduced extension of a Description Logic of typicality able to combine prototypical descriptions of concepts in order to generate new prototypical concepts and deal with problem like the PET FISH (Osherson and Smith, 1981; Lieto & Pozzato, 2019). Intuitively, in the context of our application of this logic, the (...) overall pipeline of our system works as follows: given a goal expressed as a set of properties, if the knowledge base does not contain a concept able to fulfill all these properties, then our system looks for two concepts to recombine in order to extend the original knowledge based satisfy the goal. (shrink)

Inventing novel knowledge to solve problems is a crucial, creative, mechanism employed by humans, to extend their range of action. In this paper, we present TCL (typicality-based compositional logic): a probabilistic, non monotonic extension of standard Description Logics of typicality, and will show how this framework is able to endow artificial systems of a human-like, commonsense based, concept composition procedure that allows its employment in a number of applications (ranging from computational creativity to goal-based reasoning to recommender systems and affective (...) computing). -/- The framework relies on 3 main ingredients: a non monotonic extension of standard Description Logics (allowing to reason on exceptions to inheritance in standard knowledge bases) a probabilistic extension coming from the field of logic programming (the DISPONTE semantics) a cognitive heuristics known ad HEAD-Modifier determining preference rules for the inheritance mechanisms of the novel concepts to be generated via commonsense rules. -/- We report the obtained results and the lessons learned of this research path in the context of model-based AI applications. -/- . (shrink)

My aim is to propose a better way to understand moral demandingness: a counterfactual view that requires us to consider the demands that moral theories make across other possible worlds. Seemingly, the demandingness of any moral theory or principle should be evaluated in terms of that theory’s general demandingness. This, in turn, implies that we ought to be concerned about the possible demandingness of moral theories and not just about how demanding they actually are. This counterfactual view might also have (...) some surprising implications about how demanding commonsense morality really is. After all, commonsense morality might be extremely demanding in many possible worlds. This consideration, in turn, risks undermining the commonsense moral theorist's ability to make purely cost-based demandingness objections against consequentialism, giving us strong reasons to worry about the purely cost-based demandingness objection’s viability in general. (shrink)

This paper advocates a realist position with respect to science and common sense. It considers the question of whether science provides knowledge of reality. It presents a positive response to that question. It rejects the anti-realist claim that we are unable to acquire knowledge of reality in favour of the realist view that science yields knowledge of the external world. But it remains to be specified just what world that is. Some argue that science leads to the rejection of our (...) commonsense view of the world. If so, the world about which science informs us is not the world of common sense. Common sense is “stone-age metaphysics”. It is false theory inherited from our primitive ancestors that is to be eliminated in favour of science. Against such an elimination of common sense, it is argued that science both preserves and explains our commonsense experience of the world. Science may well lead to the overthrow of some of our most deeply held beliefs. But common sense reflects a more basic and durable level of experience. Commonsense beliefs are well-confirmed beliefs that are vindicated by their role in successful practical action each and every day. Common sense provides a firm basis on which to base a realist philosophy of science. (shrink)

It is a widely held view that lying is defined in the traditional tripartite model as the conjunction of a statement, the false belief, and the intended deception. Much of the criticisms have been levelled at the third condition—intended deception—with contemporary counterexamples. My main criticism of the traditional and contemporary model of lying centres on that philosophers discard the social existence of the hearer. Schutz‘s phenomenological sociology gives a sheer inspiration to redefine the third condition by taking the hearer as (...) a consciously social being into account. Lying should be an intersubjective action for the Other from the perspective of the liar; it might be, thus, reasonable to assume that there should be commonsense awareness between the speaker and the hearer. This paper, by focusing on this commonsenseness and its typifications, introduces a new approach to the third condition: S must intend that H be induced to believe that p, where p is false. In this regard, once you lie, by being subjected to the taken-for-granted commonsenseness in our daily life, you must try as hard as possible to succeed in deceiving the hearer by stating that p. You, as a typical person, tell a typical lie in typical contexts for typical Others. The focus of attention, therefore, is on the hearer and it is the key to understanding that mere intent to deceive is too broad and unpragmatic for a social human being who always intends to flee the negative consequences of the context in which she has to lie. Making the extension narrower necessitates a new term, anti-social bullshit generally being replied rhetorically as "how can you expect me to believe that?" comprises the excluded cases. (shrink)

The Authority Account provides a new explanation why commonsense morality contains prudential options—options that permit agents to perform actions that promote their own wellbeing more than the action they have most reason to do, from the moral point of view. At the core of that explanation are two claims. The first is that moral requirements are traditionally widely taken to have an authoritative status; that is, to be rules that morality imposes by right. The second is that in order for (...) moral requirements to have such a status, morality must contain prudential options. If both of these claims are true, then they will create a pressure to think of morality as containing prudential options. And according to the Authority Account, the fact that commonsense morality contains such options is the result of this pressure. (shrink)

Preface thoroughly outlines the development and status of dark matter theory at the time of publishing this book. First chapter is like a combat between mathematical counterintuitive physics and human commonsense and explains that human commonsense equipped with proper philosophical approach is capable to deal with the problem of dark matter. Thus the first chapter makes a case for human commonsense and philosophical method.

The aim of this paper is to present and discuss the issue of the adequacy of the Minimum Intelligent Signal Test (MIST) as an alternative to the Turing Test. MIST has been proposed by Chris McKinstry as a better alternative to Turing’s original idea. Two of the main claims about MIST are that (1) MIST questions exploit commonsense knowledge and as a result are expected to be easy to answer for human beings and difficult for computer programs; and that (2) (...) the MIST design aims at eliminating the problem of the role of judges in the test. To discuss these design assumptions we will present Peter D. Turney’s PMI-IR algorithm which allows for MIST-type questions to be answered. We will also present and discuss the results of our own study aimed at the judge problem for MIST. (shrink)

This essay seeks to understand what it means for the human collective when AI technologies have become a predominant force in each of our lives through identifying three moral dilemmas (i.e., tragedy of the commons, tragedy of commonsense morality, tragedy of apathy) that shape human choices. In the first part, we articulate AI-driven versions of the three moral dilemmas. Then, in the second part, drawing from evolutionary psychology, existentialism, and East Asian philosophies, we argue that a deep appreciation of three (...) shades of human finitude can help us mitigate harmful effects of the AI-driven versions of the three tragedies and even transcend them. (shrink)

Freudian theory as an extension of commonsense psychology that is potentially cogent, cumulative, and radical.

Commonsense reasoning about the physical world, as exemplified by "Iron sinks in water" or "If a ball is dropped it gains speed," will be indispensable in future programs. We argue that to make such predictions (namely, envisioning), programs should use abstract entities (such as the gravitational field), principles (such as the principle of superposition), and laws (such as the conservation of energy) of physics for representation and reasoning. These arguments are in accord with a recent study in physics instruction where (...) expert problem solving is related to the construction of physical representations that contain fictitious, imagined entities such as forces and momenta (Larkin 1983). We give several examples showing the power of physical representations. (shrink)

Commonsense ontology often conflicts with the ontology of our best scientific and philosophical theories. However, commonsense ontology, and commonsense belief systems in general, seems to be remarkably efficient and cognitively fundamental. In cases of contrast, it is better to find a way to reconcile commonsense and ”theoretical” ontologies. Given that commonsense ontologies are typically expressed within natural language, a classical procedure of reconciliation is semantical. The strategy is that of individuating the ”ontologically problematic” expressions of natural language and paraphrasing the (...) sentences in which they appear in a (formal) language whose commitments are compatible with those of our best theories. We believe that this strategy of reconciliation, though quite standard, especially in the philosophical literature, is problematic: for a start, it forces us to conclude that the ”real content” of our commonsense expressions and beliefs is different from what it appears. Commonsense ontology becomes just an illusion. We will thus propose an alternative approach: according to our view, a commonsense ontology is reconciled with a theoretical ontology in case it is shown that the explanation of why we believe in the existence of a problematic entity is compatible with our best theories. We will call this kind of reconciliation ”epistemic”. The advantage of an epistemic reconciliation is that commonsense ontology is treated in its own right and could be taken prima facie. Another advantage of the view is that epistemic reconciliation can be analysed through the notion of explaining away: a commonsense ontology is epistemically reconciled with a theoretical ontology if and only if the problematic entities of the commonsense ontology are explained away by ”respectable” entities of the theoretical ontology. In the final part of the paper, we sketch a formal analysis of explaining away. (shrink)

Formalizing commonsense knowledge for reasoning about time has long been a central issue in AI. It has been recognized that the existing formalisms do not provide satisfactory solutions to some fundamental problems, viz. the frame problem. Moreover, it has turned out that the inferences drawn do not always coincide with those one had intended when one wrote the axioms. These issues call for a well-defined formalism and useful computational utilities for reasoning about time and change. Yoav Shoham of Stanford University (...) introduced in his 1986 Yale doctoral thesis an appealing temporal nonmonotonic logic and identified a class of theories, causal theories, which have computationally simple model-theoretic properties. This paper is a study towards building upon Shoham's work on causal theories. We concentrate on improving computational aspects of causal theories while preserving their model-theoretic properties. (shrink)