Henry D. Potter

While the free will debate tends to focus primarily on the implications of determinism for freedom, a long line of philosophers have also argued that free will would not be compatible with indeterminism either. These arguments typically take the form of a so-called Luck Objection: a family of related arguments which all seek to show, roughly, that if an action is not causally pre-determined then it must be a sort of random happening, over which the agent lacks the control required for free will. If successful, these arguments are fatal for libertarian accounts of free will, which are committed to the view that free actions must be both undetermined and under the agent’s control. In this paper, we defend libertarian free will against this challenge from luck. We argue that most formulations of the Luck Objection presuppose a conceptual model of indeterministic decision-making that is not well aligned with recent advances in the natural sciences; specifically, we argue that they make assumptions about the nature of indeterminacy and about the causal structure of decision-making, which libertarians have good empirical reason (from both physics and neuroscience) to reject. We develop a more empirically plausible model of agential decision-making and apply this to the problem of luck. We argue that, under such a model, it is entirely natural to think of an agent’s actions as both ‘undetermined’ (in the sense of being under-determined) and under their own control. We conclude that indeterminism poses no threat to a more naturalistic version of libertarian free will.

The aim of this thesis is to contribute to the project of naturalising agency, where agency can be broadly understood as the ability to choose and control one's actions on the basis of one's own purposes, goals, or reasons. Such agency is central to the basic phenomenology of our everyday existence as human beings, to how we come to understand ourselves and the world around us, and to the social, moral and legal practices that structure our societies. It is also fast becoming a critical concept for addressing emerging issues in the ethics of artificial intelligence and animal rights. Yet, despite its profound existential, societal and ethical importance, we still lack a robust understanding of the concept of agency from the perspective of the natural sciences. Part of the reason for this is a widespread and long-standing belief that agency - and related concepts such as freedom, purpose, and meaning - carry with them certain metaphysical commitments that are fundamentally incompatible with the picture of the world as it is given to us by science (what is sometimes known as a naturalistic worldview or metaphysics). This belief has led many scientists and philosophers to conclude that our concept of agency is, in fact, an illusion - a non-natural, unscientific notion that exists in our phenomenology, but not in the 'real world'. In this thesis, I push back on these conclusions by developing an empirically grounded account of biological agency. I show how several of the core features (or types) of agency that are commonly claimed to be mysterious and unscientific are in fact perfectly consistent with a modern scientific worldview. To do this, I consider a series of challenges for agency that have emerged out of the philosophy of action, behavioural neuroscience, and the philosophy of free will. Each challenge targets the scientific credibility of a particular feature of agency: specifically, (i) macroscopic, agent-level control, (ii) purposive or mental causation, and (iii) the ability to 'do otherwise' and make genuine choices. I draw on recent empirical work from across the natural sciences to argue that these features are in fact supported by modern science. I do this by developing an empirically grounded framework for thinking about living systems and their behaviour (within each of the specified contexts) which, I argue, provides an entirely naturalistic and non-mysterious account of the relevant feature of agency. That is, I argue for a novel view of naturalistic metaphysics that appears to resolve many of the existing scientific concerns about the concept of agency. I then end by considering some recent attempts to extend a similar concept of agency into the domains of developmental and evolutionary biology. I argue that, in their current form, these attempts are not successful.

The claim that organisms are the agents of their own embryonic development, actively directing their own ontogenetic trajectories towards adaptive outcomes, is central to an emerging set of heterodox perspectives within theoretical and philosophical biology. Several theoretical implications are argued to follow from this ‘agential stance,’ which present a radical challenge to standard theories and approaches in evolutionary and developmental biology. These include the following: (i) Organism-Level Control: the need for a causal framework for developmental biology that causally privileges the organism (as opposed to either privileging genes or embracing multi-level causation); (ii) Agential Adaptation: the need for an explanatory model of individual-level adaptedness that prioritises the developing organism’s active purposiveness (as distinct from adaptation by natural selection); and (iii) Agential Evolution: the need for an explanatory model of adaptive population change that prioritises the organism’s agency and purposiveness in its development (as distinct from standard models of evolution by natural selection). We argue that if the agential stance is to be interpreted literally, then its claims are not well supported by available empirical evidence. If the view is to be interpreted heuristically, then it cannot offer the sort of distinctive or novel explanatory insight needed to ground these radical implications.

In neuroscience, the search for the causes of behaviour is often just taken to be the search for neural mechanisms. This view typically involves three forms of causal reduction: first, from the ontological level of cognitive processes to that of neural mechanisms; second, from the activity of the whole brain to that of isolated parts; and third, from a consideration of temporally extended, historical processes to a focus on synchronic states. While modern neuroscience has made impressive progress in identifying synchronic neural mechanisms, providing unprecedented real-time control of behaviour, we contend that this does not amount to a full causal explanation. In particular, there is an attendant danger of eliminating the cognitive from our explanatory framework, and even eliminating the organism itself. To fully understand the causes of behaviour, we need to understand not just what happens when different neurons are activated, but why those things happen. In this paper, we introduce a range of well-developed, non-reductive, and temporally extended notions of causality from philosophy, which neuroscientists may be able to draw on in order to build more complete causal explanations of behaviour. These include concepts of criterial causation, triggering versus structuring causes, constraints, macroscopic causation, historicity, and semantic causation—all of which, we argue, can be used to undergird a naturalistic understanding of mental causation and agent causation. These concepts can, collectively, help bring cognition and the organism itself back into the picture, as a causal agent unto itself, while still grounding causation in respectable scientific terms.

Free will discourse is primarily centred around the thesis of determinism. Much of the literature takes determinism as its starting premise, assuming it true “for the sake of discussion”, and then proceeds to present arguments for why, if determinism is true, free will would be either possible or impossible. This is reflected in the theoretical terrain of the debate, with the primary distinction currently being between compatibilists and incompatibilists and not, as one might expect, between free will realists and skeptics. The aim of this paper is twofold. First, we argue that there is no reason to accept such a framing. We show that, on the basis of modern physics, there is no good evidence that physical determinism (of any variety) provides an accurate description of our universe and lots of evidence against such a view. Moreover, we show that this analysis extends equally to the sort of ‘indeterministic’ worldviews endorsed by many libertarian philosophers (and their skeptics) – a worldview which we refer to as determinism-plus-randomness. The paper’s secondary aim is therefore to present an alternative conception of indeterminism, which is more in line with the empirical evidence from physics. It is this indeterministic worldview, we suggest, that ought to be the central focus of a reframed philosophy of free will.

While the free will debate tends to focus primarily on the implications of determinism for freedom, a long line of philosophers have also argued that free will would not be compatible with indeterminism either. These arguments typically take the form of a so-called Luck Objection: a family of related arguments which all seek to show, roughly, that if an action is not causally pre-determined then it must be a sort of random happening, over which the agent lacks the control required for free will. If successful, these arguments are fatal for libertarian accounts of free will, which are committed to the view that free actions must be both undetermined and under the agent’s control. In this paper, we defend libertarian free will against this challenge from luck. We argue that most formulations of the Luck Objection presuppose a conceptual model of indeterministic decision-making that is not well aligned with recent advances in the natural sciences; specifically, we argue that they make assumptions about the nature of indeterminacy and about the causal structure of decision-making, which libertarians have good empirical reason (from both physics and neuroscience) to reject. We develop a more empirically plausible model of agential decision-making and apply this to the problem of luck. We argue that, under such a model, it is entirely natural to think of an agent’s actions as both ‘undetermined’ (in the sense of being under-determined) and under their own control. We conclude that indeterminism poses no threat to a more naturalistic version of libertarian free will.

The idea of agent causation—that a system such as a living organism can be a cause of things in the world—is often seen as mysterious and deemed to be at odds with the physicalist thesis that is now commonly embraced in science and philosophy. Instead, the causal power of organisms is attributed to mechanistic components within the system or derived from the causal activity at the lowest level of physical description. In either case, the ‘agent’ itself (i.e., the system as a whole) is left out of the picture entirely, and agent causation is explained away. We argue that this is not the right way to think about causation in biology or in systems more generally. We present a framework of eight criteria that we argue, collectively, describe a system that overcomes the challenges concerning agent causality in an entirely naturalistic and non-mysterious way. They are: (1) thermodynamic autonomy, (2) persistence, (3) endogenous activity, (4) holistic integration, (5) low-level indeterminacy, (6) multiple realisability, (7) historicity, (8) agent-level normativity. Each criterion is taken to be dimensional rather than categorical, and thus we conclude with a short discussion on how researchers working on quantifying agency may use this multidimensional framework to situate and guide their research.