The metaphor of a branching tree of future possibilities has a number of important philosophical and logical uses. In this paper we trace this metaphor through some of its uses and argue that the metaphor works the same way in physics as in philosophy. We then give an overview of formal systems for branching possibilities, viz., branching time and (briefly) branching space-times. In a next step we describe a number of different notions of possibility, thereby sketching a landscape of possibilities. (...) In the final section of the paper we look at the place of branching-based possibilities in that larger landscape of possibilities. Our main message is that far from being an outlandish metaphysical extravagancy, branching-based possibilities are epistemically as well as metaphysically basic. (shrink)

But Findlay's remark, like so much that has been written on the subject of time in the present century, was provoked in the first place by McTaggart's ...

David Hume's Enquiry concerning Human Understanding is the definitive statement of the greatest philosopher in the English language. His arguments in support of reasoning from experience, and against the "sophistry and illusion"of religiously inspired philosophical fantasies, caused controversy in the eighteenth century and are strikingly relevant today, when faith and science continue to clash. The Enquiry considers the origin and processes of human thought, reaching the stark conclusion that we can have no ultimate understanding of the physical world, or indeed (...) our own minds. In either sphere we must depend on instinctive learning from experience, recognizing our animal nature and the limits of reason. Hume's calm and open-minded skepticism thus aims to provide a new basis for science, liberating us from the "superstition" of false metaphysics and religion. His Enquiry remains one of the best introductions to the study of philosophy, and his edition places it in its historical and philosophical context. (shrink)

In this important new study Ian Hacking continues the enquiry into the origins and development of certain characteristic modes of contemporary thought undertaken in such previous works as his best selling Emergence of Probability. Professor Hacking shows how by the late nineteenth century it became possible to think of statistical patterns as explanatory in themselves, and to regard the world as not necessarily deterministic in character. Combining detailed scientific historical research with characteristic philosophic breath and verve, The Taming of Chance (...) brings out the relations among philosophy, the physical sciences, mathematics and the development of social institutions, and provides a unique and authoritative analysis of the "probabilization" of the Western world. (shrink)

This paper has two parts. In the first part, I concede an error in an argument I have given for the incompatibility of free will and determinism. I go on to show how to modify my argument so as to avoid this error, and conclude that the thesis that free will and determinism are compatible continues to be—to say the least—implausible. But if free will is incompatible with determinism, we are faced with a mystery, for free will undeniably exists, and (...) it also seems to be incompatible with indeterminism. In the second part of this paper, I will defend the conclusion that the concept of agent causation is of no use to the philosopher who wants to maintain that free will and indeterminism are compatible. I conclude that free will remains a mystery---that is, that free will undeniably exists and that there is a strong and unanswered prima facie case for its impossibility. (shrink)

The doyen of living English philosophers, by these reflections, took hold of and changed the outlook of a good many other philosophers, if not quite enough. He did so, essentially, by assuming that talk of freedom and responsibility is talk not of facts or truths, in a certain sense, but of our attitudes. His more explicit concern was to look again at the question of whether determinism and freedom are consistent with one another -- by shifting attention to certain personal (...) rather than moral attitudes, first of all gratitude and resentment. In the end, he arrived at a kind of Compatibilist or, as he says, Optimist conclusion. That is no doubt a recommendation but not the largest recommendation of this splendidly rich piece of philosophy. (shrink)

Mele's ultimate purpose in this book is to help readers think more clearly about free will. He identifies and makes vivid the most important conceptual obstacles to justified belief in the existence of free will and meets them head on. Mele clarifies the central issues in the philosophical debate about free will and moral responsibility, criticizes various influential contemporary theories about free will, and develops two overlapping conceptions of free will--one for readers who are convinced that free will is incompatible (...) with determinism (incompatibilists), and the other for readers who are convinced of the opposite (compatibilists). Luck poses problems for all believers in free will, and Mele offers novel solutions to those problems--one for incompatibilist believers in free will and the other for compatibilists. An early chapter of this empirically well-informed book clearly explains influential neuroscientific studies of free will and debunks some extravagant interpretations of the data. Other featured topics include abilities and alternative possibilities, control and decision-making, the bearing of manipulation on free will, and the development of human infants into free agents. Mele's theory offers an original perspective on an important problem and will garner the attention of anyone interested in the debate on free will. (shrink)

This chapter defends a history-sensitive compatibilist view of free action and moral responsibility against various criticisms by compatibilists. It constructs a new argument for incompatibilism that makes vivid a problem that luck poses for compatibilism: the zygote argument. It is argued that the zygote argument is much more powerful than more familiar arguments for incompatibilism, and that, even so, compatibilism may survive the attack.

Abilities are in many ways central to what being an agent means, and they are appealed to in philosophical accounts of a great many different phenomena. It is often assumed that abilities are some kind of dispositional property, but it is rarely made explicit exactly which dispositional properties are our abilities. Two recent debates provide two different answers to that question: the new dispositionalism in the debate about free will, and virtue reliabilism in epistemology. This paper argues that both answers (...) fail as general accounts of abilities, and discusses the ramifications of this result. (shrink)

The set with the following members is inconsistent: F-Lesson: A person can be blameworthy for performing an action even though she cannot refrain from performing it. Equivalence: ‘Ought not’ is equivalent to ‘impermissible.’ OIC: ‘Ought’ implies ‘can’ and ‘ought not’ implies ‘can refrain from.’ BRI: Necessarily, one is morally blameworthy for doing something only if it is overall morally impermissible for one to do it. Since Equivalence seems unassailable, one can escape the inconsistency by renouncing any one of the other (...) members. I first argue against BRI and then motivate a replacement for it that ties blameworthiness to belief in impermissibility. (shrink)

Robert Kane provides a critical overview of debates about free will of the past half century, relating this recent inquiry to the broader history of the free will issue and to vital currents of twentieth century thought. Kane also defends a traditional libertarian or incompatibilist view of free will, employing arguments that are both new to philosophy and that respond to contemporary developments in physics and biology, neuro science, and the cognitive and behavioral sciences.

Individual objects have potentials: paper has the potential to burn, an acorn has the potential to turn into a tree, some people have the potential to run a mile in less than four minutes. Barbara Vetter provides a systematic investigation into the metaphysics of such potentials, and an account of metaphysical modality based on them. -/- In contemporary philosophy, potentials have been recognized mostly in the form of so-called dispositions: solubility, fragility, and so on. Vetter takes dispositions as her starting (...) point, but argues for and develops a more comprehensive conception of potentiality. She shows how, with this more comprehensive conception, an account of metaphysical modality can be given that meets three crucial requirements: Extensional correctness: providing the right truth-values for statements of possibility and necessity; formal adequacy: providing the right logic for metaphysical modality; and semantic utility: providing a semantics that links ordinary modal language to the metaphysics of modality. -/- The resulting view of modality is a version of dispositionalism about modality: it takes modality to be a matter of the dispositions of individual objects. This approach has a long philosophical tradition going back to Aristotle, but has been largely neglected in contemporary philosophy. In recent years, it has become a live option again due to the rise of anti-Humean, powers-based metaphysics. The aim of Potentiality is to develop the dispositionalist view in a way that takes account of contemporary developments in metaphysics, logic, and semantics. (shrink)

I argue that a powers-based metaphysics radically reconfigures the existing free will problematic. This is different from claiming that such an approach solves the ill-conceived problems that emerge from Humean-Kantian default commitments.

Branching space-time is a simple blend of relativity and indeterminism. Postulates and definitions rigorously describe the causal order relation between possible point events. The key postulate is a version of everything has a causal origin; key defined terms include history and choice point. Some elementary but helpful facts are proved. Application is made to the status of causal contemporaries of indeterministic events, to how splitting of histories happens, to indeterminism without choice, and to Einstein-Podolsky-Rosen distant correlations.

It has often been noted that many of our intuitive assessments of particular actions suggest that there is an asymmetry between blameworthy and praiseworthy actions with regard to the question of whether moral responsibility requires that the agent could have acted otherwise. It is a quite different question, though, whether such an asymmetry between good and bad cases can be supported by more systematic considerations. In this paper, I will develop a new argument for a restricted version of the asymmetry, (...) by showing that in cases of praiseworthy actions responsibility cannot generally presuppose that the agent could have acted otherwise. This argument will be based on a distinction between two different kinds of roles that moral norms can play in determining whether an action is right and in guiding our deliberation. That agents can sometimes be responsible for their praiseworthy actions even though they cannot act otherwise is best seen as a reflection of the fact that moral norms can prohibit treating certain courses of action as genuine options at all. (shrink)

For those who maintain that free will is incompatible with causal determinism, a persistent problem is to give a coherent characterization of action that is neither determined by prior events nor random, arbitrary, lucky or in some way insufficiently under the control of the agent to count as free action. One approach—that of Roderick Chisholm and others—is to say that a third alternative is for an action to be caused by an agent in a way that is not reducible to (...) event causal terms. A different approach than the Chisholmian appeal to primitive substance causation is one that, instead, involves causal relations purely among events. This paper presents a particular event-causal indeterminist account of free action, describing both its attractions and recent objections to it, and then proposes a revised version, with the aim of supporting the plausibility of an event-causal indeterminist approach to free will. (shrink)

The article puts forward a branching-style framework for the analysis of determinism and indeterminism of scientific theories, starting from the core idea that an indeterministic system is one whose present allows for more than one alternative possible future. We describe how a definition of determinism stated in terms of branching models supplements and improves current treatments of determinism of theories of physics. In these treatments, we identify three main approaches: one based on the study of equations, one based on mappings (...) between temporal realizations, and one based on branching models. We first give an overview of these approaches and show that current orthodoxy advocates a combination of the mapping- and the equations-based approaches. After giving a detailed formal explication of a branching-based definition of determinism, we consider three concrete applications and end with a formal comparison of the branching- and the mapping-based approach. We conclude that the branching-based definition of determinism most usefully combines formal clarity, connection with an underlying philosophical notion of determinism, and relevance for the practical assessment of theories. 1 Introduction2 Determinism in Philosophy of Science: Three Approaches2.1 Determinism: The core idea and how to spell it out2.2 The three approaches in more detail2.3 Representing indeterminism3 Orthodoxy: DMAP, with Invocations of DEQN4 Branching-Style Determinism 4.1 Models and realizations4.2 Faithfulness4.3 Two types of branching topologies 5 Comparing the Approaches5.1 Case studies5.2 Formal comparison of the DMAP and DBRN frameworks6 Conclusions. (shrink)

Libertarians in the contemporary free will debate find themselves under attack from two angles. They face the challenge of defending the necessity of indeterminism for freedom against the philosophical mainstream position of compatibilism. And second, they are increasingly forced to argue for the very possibility of indeterministic free will, in the face of the so-called luck objection. Many contemporary libertarians try to overcome the second problem by adopting the causal theory of action. We argue that this move at the same (...) time undermines their ability to answer the first challenge. On the basis of this, we suggest that CTA might be a theory of action that is biased towards compatibilism. We thus argue that the best strategy for the libertarian is to insist that intentional action itself requires indeterminism. Recent agent-causal accounts offer a promising way of developing such an alternative libertarianism, but we argue that they currently suffer from problems similar to the ones we identify for the event-causalist. If we are correct, then this has an important implication for the contemporary free will debate: action theory should take centre stage. (shrink)

The paper describes two approaches to determinism: one focuses on the features of global objects, such as possible worlds or models of a theory, whereas the other’s concern is the possible behaviour of individual objects. It then gives an outline of an individuals-based analysis of the determinism of theories. Finally, a general relativistic spacetime with non-isometric extensions is described and used to illustrate a conflict between the two approaches: this spacetime is indeterministic by the first approach but deterministic by the (...) second approach. (shrink)

The general question to which Edwards here addresses himself is "whether any event whatsoever, and volition in particular, can come to pass without a cause of its existence," and among other arguments for a negative answer he has a reductio ad absurdum, arguing that if an act of will can occur without a cause, then anything at all, no matter how fantastic, can occur without a cause. There is, he says in effect, an inner contradiction in the notion that uncaused (...) events are bound always to be acts of will. We must note, however, in following his argument through, that his language is not quite that which I have just used, and in particular he does not speak primarily of what "occurs" but rather of what "begins to be." He says. (shrink)

The aim of this paper is to establish that free agency, which is a capacity of many animals including human beings, is compatible with indeterminism: an indeterministic world allows for the existence of free agency. The question of the compatibility of free agency and indeterminism is less discussed than its mirror image, the question of the compatibility of free agency and determinism. It is, however, of great importance for our self-conception as free agents in our (arguably) indeterministic world. We begin (...) by explicating the notions of indeterminism and free agency and by clarifying the interrelation of free agency and the human-specific notion of free will. We then situate our claim of the compatibility of free agency and indeterminism precisely in the landscape of the current debate on freedom and determinism, exposing an unhappy asymmetry in that debate. Then we proceed to make our case by describing the mathematically precise, physically motivated model of projective simulation, which employs indeterminism as a central resource for agency modeling. We argue that an indeterministic process of deliberation modeled by the dynamics of projective simulation can exemplify free agency under indeterminism, thereby establishing our compatibility claim: Free agency can develop and thrive in an indeterministic world. (shrink)

In this paper we develop a novel propositional semantics based on the framework of branching time. The basic idea is to replace the moment-history pairs employed as parameters of truth in the standard Ockhamist semantics by pairs consisting of a moment and a consistent, downward closed set of so-called transitions. Whereas histories represent complete possible courses of events, sets of transitions can represent incomplete parts thereof as well. Each transition captures one of the alternative immediate future possibilities open at a (...) branching point. The transition semantics exploits the structural resources a branching time structure has to offer and provides a fine-grained picture of the interrelation of modality and time. In addition to temporal and modal operators, a so-called stability operator becomes interpretable as a universal quantifier over the possible future extensions of a given transition set. The stability operator allows us to specify how and how far time has to unfold for the truth value of a sentence at a moment to become settled and enables a perspicuous treatment of future contingents. We show that the semantics developed along those lines generalizes and extends extant approaches: both Peirceanism and Ockhamism can be viewed as limiting cases of the transition approach that build on restricted resources only, and on both accounts, stability collapses into truth. (shrink)

In the tree-like representation of Time, two histories are undivided at a moment t whenever they share a common moment in the future of t. In the present paper, it will first be proved that Ockhamist and Peircean branching-time logics are unable to express some important sentences in which the notion of undividedness is involved. Then, a new semantics for branching-time logic will be presented. The new semantics is based on trees endowed with an indistinguishability function, a generalization of the (...) notion of undividedness. It will be shown that Ockhamist and Peircean semantics can be viewed as limit cases of the semantics developed in this paper. (shrink)

This paper studies intentional action in stit logic. The formal logic study of intentional action appears to be new, since most logical studies of intention concern intention as a static mental state. In the formalization we distinguish three modes of acting: the objective level concerning the choices an agent objectively exercises, the subjective level concerning the choices an agent knows or believes to be exercising, and finally, the intentional level concerning the choices an agent intentionally exercises. Several axioms constraining the (...) relations between these different modes of acting will be considered and discussed. The side effect problem will be analyzed as an interaction between knowingly doing and intentionally doing. Non-successful action will be analyzed as a weakening of the epistemic attitude towards action. Finally, the notion of ‘attempt’ will be briefly considered as a further weakening in this direction. (shrink)

This paper gives an overview of logico-philosophical issues of time and determinism. After a brief review of historical roots and 20th century developments, three current research areas are discussed: the definition of determinism, space-time indeterminism, and the temporality of individual things and their possibilities.

The aim of this paper is to respond to recent discussion of, and objections to, the libertarian view of free will I have developed in many works over the past four decades. The issues discussed all have a bearing on the central question of how one might make sense of a traditional free will requiring indeterminism in the light of modern science. This task involves, among other things, avoiding all traditional libertarian appeals to unusual forms of agency or causation that (...) cannot be accounted for by ordinary modes of explanation familiar to the natural and human sciences. Doing this, I argue, requires piecing together a “complex tapestry” of ideas and arguments that involve rethinking many traditional assumptions about free will. The paper also argues that one cannot get to the heart of historical debates about free will without distinguishing different kinds of freedom, different senses of will, and different notions of control, among other distinctions. I especially focus here on different notions of freedom and control that are necessary to make sense of free will. (shrink)

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. (shrink)

I argue that realism about causal powers sublates the passivist, Humean-inflected free will problematic. In the first part of the paper I show that adopting what I call ‘powers-non-determinism’ reconfigures the conceptual terrain with respect to the causation component of the contemporary problematic. In part two I show how adopting ‘powers-non-determinism’ significantly alters the nature of the discussion with respect to the agency component of the problematic. In part three I compare ‘powers-non-determinism’ to an otherwise- Humean agent causal position.

We extend stit logic by adding a spatial dimension. This enables us to distinguish between powers and opportunities of agents. Powers are agent-specific and do not depend on an agent’s location. Opportunities do depend on locations, and are the same for every agent. The central idea is to define the real possibility to see to the truth of a condition in space and time as the combination of the power and the opportunity to do so. The focus on agent-relative powers (...) and space-relative opportunities firmly roots effectivity of an autonomous choice making agent in a space–time picture. Our space–time view will be classically Newtonian, since we will assume relativistic phenomena do not play a role in agentive effectivity. We show how our semantics naturally distinguishes between different kinds of histories; histories that reflect real possibilities and histories that reflect counterfactual possibilities. Furthermore, we discuss how the spatial picture sheds light on conceptual problems plaguing the central stit property of ‘independence of agency’. At several points in the article we will emphasise and defend the differences with Belnap’s theory of agency in relativistic branching space–times. (shrink)