Language, logic and ontology: uncovering the structure of commonsense knowledge

The purpose of this paper is twofold: (i) we argue that the structure of commonsense knowledge must be discovered, rather than invented; and (ii) we argue that natural language, which is the best known theory of our (shared) commonsense knowledge, should itself be used as a guide to discovering the structure of commonsense knowledge. In addition to suggesting a systematic method to the discovery of the structure of commonsense knowledge, the method we propose seems to also provide an explanation for a number of phenomena in natural language, such as metaphor, intensionality, and the semantics of nominal compounds. Admittedly, our ultimate goal is quite ambitious, and it is no less than the systematic ‘discovery’ of a well-typed ontology of commonsense knowledge, and the subsequent formulation of the longawaited goal of a meaning algebra

Finality revived: powers and intentionality

Proponents of physical intentionality argue that the classic hallmarks of intentionality highlighted by Brentano are also found in purely physical powers. Critics worry that this idea is metaphysically obscure at best, and at worst leads to panpsychism or animism. I examine the debate in detail, finding both confusion and illumination in the physical intentionalist thesis. Analysing a number of the canonical features of intentionality, I show that they all point to one overarching phenomenon of which both the mental and the physical are kinds, namely finality. This is the finality of ‘final causes’, the long-discarded idea of universal action for an end to which recent proponents of physical intentionality are in fact pointing whether or not they realise it. I explain finality in terms of the concept of specific indifference, arguing that in the case of the mental, specific indifference is realised by the process of abstraction, which has no correlate in the case of physical powers. This analysis, I conclude, reveals both the strength and weakness of rational creatures such as us, as well as demystifying (albeit only partly) the way in which powers work

Reasoning over Taxonomic Change: Exploring Alignments for the Perelleschus Use Case

Classifications and phylogenetic inferences of organismal groups change in light of new insights. Over time these changes can result in an imperfect tracking of taxonomic perspectives through the re-/use of Code-compliant or informal names. To mitigate these limitations, we introduce a novel approach for aligning taxonomies through the interaction of human experts and logic reasoners. We explore the performance of this approach with the Perelleschus use case of Franz & Cardona-Duque (2013). The use case includes six taxonomies published from 1936 to 2013, 54 taxonomic concepts (i.e., circumscriptions of names individuated according to their respective source publications), and 75 expert-asserted Region Connection Calculus articulations (e.g., congruence, proper inclusion, overlap, or exclusion). An Open Source reasoning toolkit is used to analyze 13 paired Perelleschus taxonomy alignments under heterogeneous constraints and interpretations. The reasoning workflow optimizes the logical consistency and expressiveness of the input and infers the set of maximally informative relations among the entailed taxonomic concepts. The latter are then used to produce merge visualizations that represent all congruent and non-congruent taxonomic elements among the aligned input trees. In this small use case with 6-53 input concepts per alignment, the information gained through the reasoning process is on average one order of magnitude greater than in the input. The approach offers scalable solutions for tracking provenance among succeeding taxonomic perspectives that may have differential biases in naming conventions, phylogenetic resolution, ingroup and outgroup sampling, or ostensive (member-referencing) versus intensional (property-referencing) concepts and articulations.Comment: 30 pages, 16 figure

Reasoning over Taxonomic Change: Exploring Alignments for the Perelleschus Use Case

abstract: Classifications and phylogenetic inferences of organismal groups change in light of new insights. Over time these changes can result in an imperfect tracking of taxonomic perspectives through the re-/use of Code-compliant or informal names. To mitigate these limitations, we introduce a novel approach for aligning taxonomies through the interaction of human experts and logic reasoners. We explore the performance of this approach with the Perelleschus use case of Franz & Cardona-Duque (2013). The use case includes six taxonomies published from 1936 to 2013, 54 taxonomic concepts (i.e., circumscriptions of names individuated according to their respective source publications), and 75 expert-asserted Region Connection Calculus articulations (e.g., congruence, proper inclusion, overlap, or exclusion). An Open Source reasoning toolkit is used to analyze 13 paired Perelleschus taxonomy alignments under heterogeneous constraints and interpretations. The reasoning workflow optimizes the logical consistency and expressiveness of the input and infers the set of maximally informative relations among the entailed taxonomic concepts. The latter are then used to produce merge visualizations that represent all congruent and non-congruent taxonomic elements among the aligned input trees. In this small use case with 6-53 input concepts per alignment, the information gained through the reasoning process is on average one order of magnitude greater than in the input. The approach offers scalable solutions for tracking provenance among succeeding taxonomic perspectives that may have differential biases in naming conventions, phylogenetic resolution, ingroup and outgroup sampling, or ostensive (member-referencing) versus intensional (property-referencing) concepts and articulations.The article is published at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.011824

A Channel Theoretic Approach to Conditional Reasoning

Institute for Communicating and Collaborative SystemsChannel Theory is a recently developed mathematical model of information flow, based on ideas emanating from situation theory.Channel theory addreses a number of important properties of information flow, such as context-dependence, modularity of information, and the possibility of error.This thesis is concerned with the use of channel theory as a formal framework for various constructs relating to conditional sentences. In particular,the main concern is to obtain logics for reasoning about conditionals,generics and default properties within the channel theoretic framework

Modal auxiliary verbs and contexts

Modal auxiliary verbs, such as `could', `might', `must', `would', and others, have different readings depending on the context in which they occur (Kratzer 1981). The sentence `Jess could fry the fish' can mean that, in a time previous to the utterance of the sentence, Jess had the ability to fry the fish, or it can mean that, at the time of the utterance, Jess frying the fish is a possible event. Modal auxiliary verbs often create intensional environments, leading the events described by the second verb to be understood to be non-actual events. When the readings are described as being determined by a context, it is often a broad notion of non-linguistic and extra-sentential linguistic context that is the focus of the interpretation. For example, descriptive pragmatic constraints are used in Lewis 1973 and Kratzer 1981 to characterize types of accessibility relations and types of orderings of worlds. A large part of the meaning of modal auxiliary verbs, however, centers around how the events described by the second verb are situated relative to the time at which the sentence containing the modal auxiliary is used. Information about the temporal situation of an event is conveyed through the linguistic context in which a modal auxiliary verb occurs, including, but not limited to, lexical properties of the linguistic expressions describing the event in the scope of the modal auxiliary, lexical properties of the modal auxiliary itself, and temporal and aspectual marking on linguistic expressions in the verbal projections. In order to provide a framework for representing the interactions of tense, aspect, and modality, a fragment of English is given in a Multi-Modal Combinatorial Categorial Grammar (Baldridge & Kruijff, Steedman 2012). Modal auxiliaries are given verb-like lexical entries in the grammar using lexical entries that combine features from Villavicenio 2002 and standard attribute value matrices of Head Driven Phrase Structure Grammar (Pollard & Sag 1999, Sag, Wasow, & Bender 2003). Modal auxiliaries have default lexical arguments with which they combine, and they combine with temporal and aspectual meaning that is sometimes morphologically manifested through grammatical tense and aspect. Portions of the combinatory methods are based on Bach 1983, who argued for less constrained combinatorial rules and unification of features in order to represent modal auxiliaries. The notion of event semantics (Davidson 1967) plays an important role in the formulation of the compositional semantics due to the way in which event times are related to aspectual meaning. The grammar uses a Neo-Davidsonian approach (Parsons 1990) to representing the arguments of the verb and builds on the work of Champollion 2015. The temporal component is very important in this work and uses portions of the temporal and event ontology proposed in Muskens 1995, 2003. Two paradigms of modal auxiliaries are proposed: Tense-bearing modal auxiliaries and non-tense-bearing modal auxiliaries. Within each paradigm, readings are shown to have differing semantics with respect to the semantic roles with which they combine and the temporal and aspectual readings that they can have. Differing results with respect to their behaviour in describing various states of affairs are addressed as is their behaviour in expressing past tense, sequence of tense contexts (Abusch 1997), and the distribution of perfect aspect. The formal grammar distinguishes parts of the meaning of sentences with modal auxiliary verbs that can be represented in terms of composition of temporal and aspectual expressions with modal auxiliary verbs or composition of a modal auxiliary verb with its arguments on one hand from parts of the meaning that are constrained by a broader notion of context, on the other hand. The notion of a broader context is not, however, neglected in the treatment. The English language fragment presented in the grammar is interpreted in a relativist semantic model, motivated by the assessment-sensitivity of epistemic modal auxiliaries (MacFarlane 2011, Lasersohn 2005, Lasersohn 2015). Readings that do not require assessment sensitivity are given truth conditions according to those given for monadic truth in Lasersohn 2015. The interaction of readings with their grammatical distribution provides additional theoretical insights into the linguistic contexts that are conducive to assessment sensitivity, actuality inferences, and counterfactual readings. Most notably, it is shown that assessment sensitivity is only present in modal auxiliaries that are in the non-tense-bearing paradigm. Parts of the theoretical treatment presented in this work have been applied in areas of automated classification of modal auxiliary verbs (Moon 2011, Moon 2012, Moon et al. 2016), showing that temporal, aspectual, and argument structure information can be used to determine the most likely reading of a modal auxiliary at the sentence level, increasing the ease of reading identification for automated tools