Peter Øhrstrøm

Some very good arguments can be given in favor of the Augustinean wisdom, according to which it is impossible to provide a satisfactory definition of the concept of time. However, even in the absence of a proper definition, it is possible to deal with conceptual problems regarding time. It can be done in terms of analogies and metaphors. In particular, it is attractive to make use of Peirce's diagrams by means of which various kinds of conceptual experimentation can be carried out. This paper investigates how Peircean diagrams can be used within the study of time. In particular, we discuss 1) the topological properties of time, 2) the implicative structure in tense logic, 3) the notions of open future and branching time models, and finally 4) tenselogical alternatives to branching time models.

The basic claim of intelligent design is that some significant problems inherent in the core of the scientific theories about the origin of life are being neglected in the mainstream of modern epistemology, scientific thinking, and philosophy of science. The advocates of the intelligent design hold that certain features of the universe and of living things can only be explained by an intelligent cause, not just be reference to an undirected process such as natural selection. They also hold that a proper description of nature should include the notion of 'purpose' i.e. that teleological descriptions should not in principle be excluded from the scientific literature. A great majority of the scientific community rejects the scientific validity and relevance of these claims. On the other hand, the idea of intelligent design has given rise to some interesting epistemological, methodological, and ontological questions, which are relevant for the formulation and understanding of science. In this book a group of scientists and philosophers discuss these questions. Some of the authors defend the basic ideas of intelligent design while others oppose these ideas.

This paper examines a 1996 debate with Nuel Belnap on the thin red line (TRL) in branching-time semantics. While A.N. Prior’s tense-logic did not incorporate a privileged future, he discussed the idea as a possible interpretation of Ockham’s logic. The TRL asserts that one future among many is “true”, preserving bivalence, but Belnap and Green (Philos Perspect 8:365–388, 1994) argued that this contradicts indeterminism. The paper explores the origins of the term “thin red line”, Belnap and Green’s objections, and refinements to the TRL, conceived as a dynamic function for selecting a privileged chronicle at each moment in a branching time model. It also examines Belnap’s response to these refinements and situates the debate within broader discussions on Ockhamism and Molinism.

This paper is a critical discussion of A.N. Prior’s contribution to the modern understanding of indeterminism and human freedom of choice. Prior suggested that these ideas should be conceived in terms of his tense logic. It can be demonstrated that his approach provides an attractive formalization that makes it possible to discuss indeterminism and human freedom of choice in a very precise manner and in a broader metaphysical context. It is also argued that Prior’s development of this approach was closely linked to his very personal struggles with fundamental religious and metaphysical questions. In his opinion, holding the doctrine of divine foreknowledge together with the doctrine of human freewill gives rise to difficult logical and philosophical problems. It appears that Prior, rather early on, decided to support what was later known as the Peircean solution, although he also analysed what he considered to be the most important alternative solution—the Ockhamist solution. This paper offers a discussion of some of Prior’s published books and papers as well as some of the papers in his Nachlass.

Arthur Norman Prior (1914 – 1969) and Georg Henrik von Wright (1916 – 2003) both attended a conference in England sometime in the spring of 1956, after which they corresponded on Anselm’s ontological argument. Prior had at the conference presented a formal treatment of the ontological argument. Based upon notes from the Prior archive at the Bodleian Library, and correspondence with von Wright, we here presents Prior’s and von Wrights’ discussion of Anselm’s argument in light of Prior’s published, as well as unpublished writings on the ontological argument. Three versions of the ontological argument from Prior’s unpublished as well as published papers is presented: a non-modal, an argument from possible existence and finally a modal version. While Prior dismissed the first on the basis of a meta-theorem for proof in argumentation, the second on the basis of a fallacious commutation of operators, he argued that a valid version of the ontological argument can be proven from the distinctive S5 thesis of Lewis modal logic. While Prior gave reasons for a rejection of those distinct S5 thesis, in favour of Lewis S4 system, he also provided a novel argument in favour of accepting the S5 thesis for necessity and possibility. Finally we relate Prior’s work to Plantinga (1974) and consider objections raised by Oppy (2012) and Gale (2007) toward the modal versions of the ontological argument.

In his philosophy, William of Ockham (1285-1347) offered an important and detailed response to the classical argument from the truth of a statement regarding the future to the necessity (unpreventability) of the statement. In this paper, Ockham’s solution and the possible formalisation of it are discussed in terms of modern tense and modal logic. In particular, the famous branching time formalisation suggested by A.N. Prior (1914-19) is discussed. Weaknesses and problems with this suggestion are pointed out, and an alternative formalisation of Ockham’s solution without the use of branching time is presented.

Logic has sometimes been seen as an alternative to metaphysics and to speculation. In this paper it is argued that a different story should be told when it comes to temporal logic and tense-logic in particular. A. N. Prior’s first formulation of tense logic was mainly established in order to qualify the discussion of certain metaphysical and conceptual problems. Although temporal logic has now been developed in various abstract and rather technical ways, it may still serve as a great help for anyone who wants to clarify the discussion of important existential questions like the nature of time, determinism, future contingency or freedom of choice.

This book is an edited collection of papers from international experts in philosophy and psychology concerned with time. The collection aims to bridge the gap between these disciplines by focussing on five key themes and providing philosophical and psychological perspectives on each theme. The first theme is the concept of time. The discussion ranges from the folk concept of time to the notion of time in logic, philosophy and psychology. The second theme concerns the notion of present in the philosophy of mind, metaphysics, and psychology. The third theme relates to continuity and flow of time in mind. One of the key questions in this section is how the apparent temporal continuity of conscious experience relates to the possibly discrete character of underlying neural processes. The fourth theme is the timing of experiences, with a focus on the perception of simultaneity and illusions of temporal order. Such effects are treated as test cases for hypotheses about the relationship between the subjective temporal order of experience and the objective order of neural events. The fifth and the final theme of the volume is time and intersubjectivity. This section examines the role of time in interpersonal coordination and in the development of social skills. The collection will appeal to both psychologists and philosophers, but also to researchers from other disciplines who seek an accessible overview of the research on time in psychology and philosophy.

Current genetics studies often refer to notions from information science. The purpose of this paper is to summarize and structure the different notions of information used in biology, as a step towards developing a taxonomy of information. Within this framework we propose an extension of Floridi’s conceptual model of information. We also make use of the concept of specified information and show that functional information and many other notions of information are either special cases of, or are closely related to, specified information. Since functionality of the proteins that genes code serves as an external and independent specification, this makes it possible to define genetic information in a way that includes semantic aspects. In particular, we discuss how to understand the qualitative aspects of genetic information, how to measure its quantitative aspects, and how variants of Shannon’s information measure can be applied to molecular sequence data of protein families. While a mathematical framework may not be able to incorporate all that is included within biological information, some aspects of it allow for statistical modelling. This is especially true if we restrict our focus on the discipline of genetics. The concept of genetic information is still disputed because it attributes semantic traits to what seems to be regular biochemical entities. Some researchers maintain that the use of information in biology is just metaphorical and may even be misleading. We argue that the foundation of the metaphorical view is relatively weak given the current findings in bioinformatics and show that the present understanding of genetics fits well into the context of the modern philosophy of information. The paper concludes that informational concepts have robust scientific applications at the level of genes.

PurposeHelping Autism‐diagnosed teenagers navigate and develop socially (HANDS) is an EU research project in progress. The aim of HANDS is to investigate the potential of persuasive technology as a tool to help young people diagnosed, to whatever degree, as autistic. The HANDS project set out to develop mobile ICT solutions to help young people with autism become more fully integrated into society and the purpose of this paper is to present an overview of the design behind the HANDS toolset.Design/methodology/approachThe topic of credibility is approached from an analytical, as well as an ethical, angle in order to address issues of credibility in relation to designing assistive technological tools. In addition, the authors set out to explore possible ways in which credibility can be evaluated. The paper presents a preliminary method for the evaluation of credibility; but which requires further refinement, as well as empirical support in order to inform us about issues of system credibility. Therefore, the suggested method reflects a working hypothesis which may serve as a springboard for further investigation.FindingsThe authors propose a preliminary method which reveals the necessity of certain preconditions requisite for evaluating the credibility of a system; and, in this way, seek to establish an ethically sound evaluation procedure for analysing credibility, by combining quantitative (i.e. electronic footprints) and qualitative assessments (i.e. dialogue between teacher and learner) of system credibility.Research limitations/implicationsFurther investigation of the evaluation process is needed to develop a standard for resolving the credibility of a system. Naturally, such a standard would serve not only as a tool for measuring credibility but also as a didactic tool for scaffolding a pedagogic dialogue between teacher and learner. It becomes important, therefore, to undertake the task of developing this standard in collaboration with the teachers in the HANDS project.Originality/valueThe paper discusses credibility issues and ethical concerns with a view to designing mobile solutions for autism‐diagnosed teenagers. The ideas expressed and developed herein are applicable to many assistive, technological tools available to persons with special needs.

Purpose – The purpose of this paper is to explore artificial moral agency by reflecting upon the possibility of a Moral Turing Test (MTT) and whether its lack of focus on interiority, i.e. its behaviouristic foundation, counts as an obstacle to establishing such a test to judge the performance of an Artificial Moral Agent (AMA). Subsequently, to investigate whether an MTT could serve as a useful framework for the understanding, designing and engineering of AMAs, we set out to address fundamental challenges within the field of robot ethics regarding the formal representation of moral theories and standards. Here, typically three design approaches to AMAs are available: top-down theory-driven models and bottom-up approaches which set out to model moral behaviour by means of models for adaptive learning, such as neural networks, and finally, hybrid models, which involve components from both top-down and bottom-up approaches to the modelling of moral agency. With inspiration from Allen and Wallace (2009, 2000) as well as Prior (1949, 2003), we elaborate on theoretically driven approaches to machine ethics by introducing deontic tense logic. Finally, within this framework, we explore the character of human interaction with a robot which has successfully passed an MTT. Design/methodology/approach – The ideas in this paper reflect preliminary theoretical considerations regarding the possibility of establishing a MTT based on the evaluation of moral behaviour, which focusses on moral reasoning regarding possible actions. The thoughts reflected fall within the field of normative ethics and apply deontic tense logic to discuss the possibilities and limitations of artificial moral agency. Findings – The authors stipulate a formalisation of logic of obligation, time and modality, which may serve as a candidate for implementing a system corresponding to an MTT in a restricted sense. Hence, the authors argue that to establish a present moral obligation, we need to be able to make a description of the actual situation and the relevant general moral rules. Such a description can never be complete, as the combination of exhaustive knowledge about both situations and rules would involve a God eye’s view, enabling one to know all there is to know and take everything relevant into consideration before making a perfect moral decision to act upon. Consequently, due to this frame problem, from an engineering point of view, we can only strive for designing a robot supposed to operate within a restricted domain and within a limited space-time region. Given such a setup, the robot has to be able to perform moral reasoning based on a formal description of the situation and any possible future developments. Although a system of this kind may be useful, it is clearly also limited to a particular context. It seems that it will always be possible to find special cases (outside the context for which it was designed) in which a given system does not pass the MTT. This calls for a new design of moral systems with trust-related components which will make it possible for the system to learn from experience. Originality/value – It is without doubt that in the near future we are going to be faced with advanced social robots with increasing autonomy, and our growing engagement with these robots calls for the exploration of ethical issues and stresses the importance of informing the process of engineering ethical robots. Our contribution can be seen as an early step in this direction.

In 1954, on the 27th August, Arthur Norman Prior presented his ideas of tense-logic1 for the first time. He developed the field further in many publications until his death in 1969. His books Time and Modality (1957a), Past, Present and Future (1967), and Papers on Time and Tense (1968) were clearly vital milestones. Much of Prior’s personal motivation had to do with his struggle with the logical tension between the theological doctrines of divine foreknowledge and human freedom. It turned out that tense-logic gave rise to a powerful tool for dealing with this and similar problems. Furthermore, important highlights in Prior’s tense-logic were the development of branching time and the introduction of instant propositions (leading to what has later been called ‘hybrid logic’). Since Prior’s death, many further developments of formal tense- logic and its semantics have been presented and carefully investigated. In philosophical logic, many researchers have focused on discussions regarding ‘the true future’ and the notion of ‘the thin red line’.

This review article offers a discussion of some aspects of the historical and conceptual context when the term “ontology” (Lat. ontologia) was first introduced in the scholarly circles of the early 17th century. In particular, Barry Smith's (2022) analysis of the birth of ontology provides a springboard for some further remarks on the author of the work with the first known occurrence of the word “ontologia”, Jacob Lorhard, including an analysis of his relationship with earlier philosophers Petrus Ramus and Clemens Timpler.

Temporal Logic: From Ancient Ideas to Artificial Intelligence deals with the history of temporal logic as well as the crucial systematic questions within the field. The book studies the rich contributions from ancient and medieval philosophy up to the downfall of temporal logic in the Renaissance. The modern rediscovery of the subject, which is especially due to the work of A. N. Prior, is described, leading into a thorough discussion of the use of temporal logic in computer science and the understanding of natural language. Temporal Logic: From Ancient Ideas to Artificial Intelligence thus interweaves linguistic, philosophical and computational aspects into an informative and inspiring whole.

This paper deals with the historical and philosophical background of the introduction of the notion of branching time in philosophical logic as it is revealed in the hitherto unpublished mail-correspondence between Saul Kripke and A.N. Prior in the late 1950s. The paper reveals that the idea was first suggested by Saul Kripke in a letter to A.N. Prior, dated September 3, 1958, and it is shown how the elaboration of the idea in the course of the correspondence was intimately intervowen with considerations of how to represent indeterminism and of the adequacy of tensed logic in light of special relativity. The correspondence underpins the point that Prior's later development of branching time may be understood as a crucial part of his attempt at the formulating a conceptual framework integrating basic human notions of time and free choice

Much has been written through the years of the clash between Darwinism and natural theology, and the basic tenants of this debate are well understood (Gillispie 1959; Bowler 1977; Ruse 2003; McGrath 2011). However, the literature is still growing, and one may wonder if anything new may yet be added. Of these new literary sources, one of the richest is the online Darwin Correspondence Project, which makes it possible to search and read the full texts of all correspondence either sent or received by Darwin, up to the year 1868. (This project is ongoing and letters are still being recovered and added.) The purpose of this article is to outline the role of the intelligent design argument, as espoused by its principal ..