Bradford Saad

To defend the physical reducibility of phenomenology in our world, reductive physicalists have long guarded the realm of metaphysical possibility: for decades now, they have relentlessly endeavored to prevent zombies (physical duplicates of actual conscious individuals) from entering modal space. In contrast, reductive physicalists have tended to adopt an open modal borders policy towards aliens, i.e. individuals with phenomenal properties foreign to our world. On the face of it, aliens—and, even aliens with physically irreducible phenomenology—pose no threat: after all, reductive physicalism says nothing about the nature of uninstantiated phenomenal properties. However, I argue that an alien threat looms. The trouble, for reductive physicalists, is that upon granting aliens entry into modal space, phenomenal commonalities between aliens and actual individuals arise and resist physical reduction at our world. This is the alien phenomenology problem. It could be solved by restricting access to modal space. Or by limiting what aliens can do once inside. However, these solutions harbor hidden costs for reductive physicalists, ones they should not be eager to pay. A better bargain, I suggest, would be for reductive physicalists to retreat to quasi-reductive physicalism, a form of grounding physicalism on which only some instantiated phenomenal properties are physically reducible. For reductive physicalists, this fallback position has much to offer. It enjoys reductive physicalism’s motivations. It reconciles the physical reducibility of some phenomenology in our world with the possibility of aliens. And it enables an alien-assisted defense against zombies.

Phenomenal consciousness seems fragmented: phenomenal states seem to belong to many families, where members of each family just resemble members of that family. This paper argues that phenomenal fragmentation poses a neglected problem for consciousness fundamentalism. Consciousness fundamentalism holds that some phenomenal states are fundamental and that they ground any non-fundamental phenomenal states. While consciousness fundamentalism is not a familiar view, it encompasses familiar forms of dualism, panpsychism, and idealism. Roughly, the problem is: on consciousness fundamentalism, phenomenal fragmentation leads to a radical and highly objectionable expansion of our fundamental ontology. After developing the phenomenal fragmentation problem, I survey candidate solutions and illustrate how the problem offers a fruitful constraint on theorizing about consciousness for consciousness fundamentalists.

According to the Self-Indication Assumption (SIA), learning that you are an observer should make you more confident in hypotheses that posit more observers. SIA suggests a straightforward argument for multiverse hypotheses. The argument is of distinctive interest because it supports multiverse hypotheses using a mundane observation, not fine-tuning, quantum mechanics, or modal metaphysics. However, SIA is controversial: whereas many worry that SIA yields overly strong armchair verdicts about matters that call for empirical investigation, others are drawn to SIA as an antidote to the doomsday argument. This chapter contests the standard story about SIA’s motivations and problems and offers an alternative approach to SIA: we argue that SIA can be understood as a form of induction, that we should compromise between different versions of SIA, and that this approach offers solutions to problems for SIA and an appropriately modest version of the SIA argument for multiverse hypotheses.

What would it take for AI systems to have moral standing, and what kind of obligations might fall on us as a result? This paper summarizes contemporary debates related to these questions. Topics include: how different theories of the basis of moral standing might apply to AI systems; what kind of moral importance our treatment of AI systems might have if they have any moral standing at all; possible tensions between respecting the moral status of future AI systems and the goal of achieving AI alignment; economic and political rights; the significance of empirical and moral uncertainty; and what practical measures, if any, should be implemented now to address the possibility that AI systems exhibiting morally significant mental states might appear within the not-too-distant future – assuming they are not already here.

This paper introduces and clarifies an intuitive yet neglected hypothesis: the attention-welfare link, according to which (roughly) the degree of attention directed towards valenced experiences modulates the degree to which these experiences are good or bad for their subject. We show that the link is supported by reflection on cases and that it is best understood in terms of phenomenal attention rather than functional attention. To conclude, we describe three applications of the link: first, it provides grounds for rejecting popular sentientist views of welfare; second, it sheds light on how to understand the resonance constraint; and third, it points towards a previously-unappreciated path to individuals with super-human welfare capacity.

This paper provides a contemporary introduction to issues in the philosophy of mind and cognitive science that are studied within the emerging field of digital minds research. We explore the potential for AI systems to have mental states. Questions that we address include whether AI systems can be phenomenally conscious and whether they can have propositional attitudes such as belief and desire. We also consider how digital minds might persist through time in a manner akin to how humans have personal identity through time. Along the way, we highlight methodological issues raised by these questions and examine how these questions relate to traditional issues in the philosophy of mind and cognitive science. We conclude by highlighting issues in this area that are ripe for further investigation.

On some cosmological models, we’re cosmically early: we arrived roughly 14 billion years after the Big Bang in a universe that will evidently remain conducive to the emergence of intelligent observers for trillions of years. Why are we so early? I’ll survey two broad classes of responses: large-world responses that turn on reality being much larger than on standard single-universe hypotheses and small-world responses that are compatible with the world being no larger than such hypotheses take it to be. One upshot will be that cosmic earliness suggests a diverse range of large-world explanations. In contrast, it turns out to be difficult to account for cosmic earliness while steering clear of large-world commitments. I conclude with some reflections on why our time of arrival seems thoroughly entangled with our world’s size.

Whether AI systems could be conscious is often thought to turn on whether consciousness is closely linked to biology. Roughly, the thought is: if consciousness is closely linked to biology, then AI consciousness is impossible; and if consciousness is not closely linked to biology, then AI consciousness is possible—or, at any rate, it’s more likely to be possible. A clearer specification of the kind of link between consciousness and biology that is crucial for the possibility of AI consciousness would facilitate inquiry into the prospects for AI consciousness. After motivating desiderata that such a specification should meet, I argue that proposed views about the relationship between consciousness and biology tend not to capture such a crucial link. In addition, I offer a thesis that does capture the link: the biological requirement according to which being conscious at least nomically requires having biological states.

As ever more advanced digital systems are created, it becomes increasingly likely that some of these systems will be digital minds, i.e. digital subjects of experience. With digital minds comes the risk of digital suffering. The problem of digital suffering is that of mitigating this risk. We argue that the problem of digital suffering is a high stakes moral problem and that formidable epistemic obstacles stand in the way of solving it. We then propose a strategy for solving it: Access Monitor Prevent (AMP). AMP uses a ‘dancing qualia’ argument to link the functional states of certain digital systems to their experiences—this yields epistemic access to digital minds. With that access, we can prevent digital suffering by only creating advanced digital systems that we have such access to, monitoring their functional profiles, and preventing them from entering states with functional markers of suffering. After introducing and motivating AMP, we confront limitations it faces and identify some options for overcoming them. We argue that AMP fits especially well with—and so provides a moral reason to prioritize—one approach to creating such systems: whole brain emulation. We also contend that taking other paths to digital minds would be morally risky.

This report presents findings from an expert survey on digital minds takeoff scenarios. The survey was conducted in early 2025 with 67 experts in digital minds research, AI research, philosophy, forecasting, and related fields. Participants provided probabilistic forecasts and qualitative reasoning on the development, characteristics, and societal impact of digital minds, that is, computer systems capable of subjective experience. Experts assigned high probability to digital minds being possible in principle (median 90%) and being created this century (65% by 2100), with a non-negligible probability of emergence by 2030 (20%). Many anticipated rapid growth in digital mind welfare capacity, with collective welfare capacity potentially matching that of billions of humans within a decade after the creation of the first digital mind. Participants also expected widespread claims from digital minds regarding their consciousness and rights, and predicted substantial societal disagreement over their existence and moral interests. Views diverged on whether digital mind welfare will be net positive or negative. These findings provide evidence that bears on the extent to which preparing the world for the potential arrival of digital minds should be a priority across domains such as research and governance. However, these findings should be interpreted cautiously in light of the potential for systematic overrepresentation of experts who deem digital minds particularly likely or important.

Many philosophers and scientists take cosmological fine-tuning—roughly the fact that our universe would have been devoid of life if it had had slightly different cosmological parameters—to point to the existence of a designer or multiverse. Planetary fine-tuning—roughly the fact that our planet would have been devoid of life if it had slightly different intrinsic characteristics or relations to other objects in the solar system—points to the existence of many planets. It may seem that since astronomy independently confirms the existence of many planets, planetary fine-tuning is of less philosophical interest than cosmological fine-tuning. This paper shows that any such appearance is illusory by defending four arguments for the conclusion that our planetary fine-tuning evidence supports the existence of a multiverse.

This paper argues for granular permissivism, roughly the view that evidence is sometimes permissive between doxastic attitudes at different levels of grain. The argument identifies three sources of rational slack between granularly differing doxastic states: doxastic tidiness, safety, and evidential responsiveness. After arguing for granular permissivism and contrasting it with a more familiar, Jamesian form of permissivism, I show how granular permissivism offers an escape from some arguments against permissivism. I conclude by drawing out implications from granular permissivism for questions about the value of rationality and rational constraints on deference.

We happen to live in a world in which people stand in long chains of care: some people care about other people, who care about still other people, and so on. We explore an argument according to which chains of care expand the circle of prudential concern for carers. The argument’s upshot is that many individuals have a circle of prudential concern that encompasses the welfare of many people, including distant strangers. This result has a range of surprising implications about the scope of prudential concern and our ability to know and control the determinants of our welfare. Natural extensions of the argument suggest that our welfare is—to a surprising degree—dependent on the welfare of distant strangers. We consider several proposals for escaping this outcome. It turns out that they are either costly or that they do not provide an escape. We thus provisionally accept that, courtesy of care chains, our significant prudential interests include the welfare of individuals we do not care about or even know.

We argue that AIs will plausibly soon possess a form of moral agency—interest-conferring agency—that bestows them with distinctive moral interests (rights, welfare). This fact has important ethical consequences because the emergence of agency-conferred interests in AIs will bring with it the potential for dystopian moral catastrophes. We identify and describe three in particular. First, there is a threat of artificial absurdity, a condition in which AIs have self-conceptions that are disconnected from reality in a way that detracts significance from their lives. Second, there are oppressive scenarios in which AI’s have rights that are grounded in their agency and violated on a large scale. Third, there are distributive disasters in which the distribution of different forms of moral agency results in an unjust society. We contend that these risks deserve to be considered alongside more familiar existential and suffering risks, and that urgent steps must be taken to mitigate them in order to avoid a digital dystopia.

Dualism holds that experiences somehow arise from physical states, despite being neither identical with nor grounded in such states. This paper motivates a stringent set of constraints on constructing a dualist theory of experience. To meet the constraints, a dualist theory must: (1) construe experiences as causes of physical effects, (2) ensure that experiences do not cause observable violations of the causal closure of the physical domain, (3) avoid overdetermination, (4) specify a set of psychophysical laws that yield experiences as a function of physical states, and (5) ensure that functional duplication preserves phenomenology. After motivating these constraints and explaining why existing dualist theories satisfy only some of them, I construct a dualist theory that satisfies all of them. On the resulting theory—which I call delegatory dualism—experiences uphold causal responsibilities “delegated” to them by physical states.

A causal argument for physicalism is widely held to pose a problem for dualism. This view has an unobvious presupposition, namely that the causal closure of the physical has a special sort of ground. The requisite sort of ground must distinguish the causal argument for physicalism from many defective causal arguments. On behalf of physicalists, I develop an account of the ground for the causal closure of the physical, thereby putting the causal argument for physicalism back in the business of causally problematizing dualism. One consequence of my account is that physicalists can pose a causal problem for dualism using a much weaker closure premise than is generally assumed.

A morally acceptable course of AI development should avoid two dangers: creating unaligned AI systems that pose a threat to humanity and mistreating AI systems that merit moral consideration in their own right. This paper argues these two dangers interact and that if we create AI systems that merit moral consideration, simultaneously avoiding both of these dangers would be extremely challenging. While our argument is straightforward and supported by a wide range of pretheoretical moral judgments, it has far-reaching moral implications for AI development. Although the most obvious way to avoid the tension between alignment and ethical treatment would be to avoid creating AI systems that merit moral consideration, this option may be unrealistic and is perhaps fleeting. So, we conclude by offering some suggestions for other ways of mitigating mistreatment risks associated with alignment.

Dualism holds that experiences and physical states are distinct in that neither sort of state is identical with or grounded in the other. Cognitive phenomenal realism holds that cognitive experiences are irreducible to sensory experiences. While dualism and cognitive phenomenal realism are logically orthogonal and usually discussed separately, I argue that dualism’s plausibility is sensitive to whether cognitive phenomenal realism is true. In particular, I argue that if cognitive phenomenal realism is true, then it bolsters the case for dualism via a cognitive knowledge argument that has several advantages over the standard sensory knowledge argument.

The multiverse theodicy proposes to reconcile the existence of God and evil by supposing that God created all and only the creation-worthy universes and that some universes like ours are, despite their evils, creation-worthy. Drawing on work in population ethics, this paper develops a novel challenge to the multiverse theodicy. Roughly, the challenge contends that the axiological underpinnings of the multiverse theodicy harbor a ‘mere addition paradox’: the assumption that creating creation-worthy universes would always make the world better turns out to have morally repugnant consequences akin to those of the assumption that adding worthwhile lives to a population would always make the overall welfare of the population better. Further, the challenge leverages this difficulty into an argument against God’s having created all and only the creation-worthy universes, and hence against the multiverse theodicy. Responses to this challenge are considered but found wanting, largely because of commitments of the multiverse theodicy that have no analogs in population ethics.

Dualism holds that experiences are non-physical states that exist alongside physical states. Dualism leads to the postulation of psychophysical laws that generate experiences by operating on certain sorts of physical states. What sorts of physical states? To the limited extent that dualists have addressed this question, they have tended to favor a brain-based approach that locates the physical basis of experience in the head. In contrast, this paper develops an argument for a form of dualism on which experience has a physical basis that reaches out into the world. Specifically, the argument uses a puzzle about spatial experience to support a theory I call _tracking dualism_. On tracking dualism, a psychophysical law generates experiences by operating on complex physical states that involve both brain states and tracking relations that they bear to features of the environment. To develop the argument, I discuss tracking dualism alongside its more familiar physicalist counterpart, the tracking intentionalist theory associated with Dretske, Lycan, and Tye. I conclude by outlining a tracking dualist research agenda.

In this article I argue that we should be prudentially and morally biased toward earlier events: other things equal, we should prefer for good events to occur earlier and disprefer for bad events to occur earlier. The argument contends that we should accord at least some credence—if only a small one—to a theoretical package featuring the growing block theory of time and that this package generates a presumptive bias toward earlier events. Rival theoretical packages are considered. Under reasonable allocations of credence to them, the presumptive bias escapes defeat. The argument has several corollaries: other things equal, we should be biased toward the past over the future, the further past over the nearer past, and the nearer future over the further future.

Our universe features a harmonious match between laws and states: applying its laws to its states generates other states. This is a striking fact. Matters might have been otherwise. The universe might have been stillborn in a state unengaged by its laws. The problem of nomological harmony is that of explaining the noted striking fact. After introducing and developing this problem, we canvass candidate solutions and identify some of their virtues and vices. Candidate solutions invoke the likes of a designer, axiarchic meta-laws, multiverses, essential causal powers, and Humean laws.

Some physical theories predict that almost all brains in the universe are Boltzmann brains, i.e. short-lived disembodied brains that are accidentally assembled as a result of thermodynamic or quantum fluctuations. Physicists and philosophers of physics widely regard this proliferation as unacceptable, and so take its prediction as a basis for rejecting these theories. But the putatively unacceptable consequences of this prediction follow only given certain philosophical assumptions. This paper develops a strategy for shielding physical theorizing from the threat of Boltzmann brains. The strategy appeals to a form of phenomenal externalism about the physical basis of consciousness. Given that form of phenomenal externalism, the proliferation of Boltzmann brains turns out to be benign. While the strategy faces a psychophysical fine-tuning problem, it both alleviates cosmological fine-tuning concerns that attend physics-based solutions to Boltzmann brain problems and pays explanatory dividends in connection with time’s arrow.

This paper defends the view that discovering that our universe is fine-tuned should make us more confident that other universes exist. My defense exploits a distinction between ideal and non-ideal evidential support. I use that distinction in concert with a simple model to disarm the most influential objection—the this-universe objection—to the view that fine-tuning supports the existence of other universes. However, the simple model fails to capture some important features of our epistemic situation with respect to fine-tuning. To capture these features, I introduce a more sophisticated model. I then use the more sophisticated model to show that, even once those complicating factors are taken into account, fine-tuning should boost our confidence in the existence of other universes.

Experiences tend to be followed by states for which they provide normative reasons. Such harmonious correlations cry out for explanation. Theories that answer or diminish these cries thereby achieve an advantage over theories that do neither. I argue that the main lines of response to these cries that are available to biological theorists—theorists who hold (roughly) that conscious subjects are generally biological entities—are problematic. And I argue that panpsychism—which holds (roughly) that conscious subjects are ubiquitous in nature—provides an attractive response to these explanatory cries. Taken together, these considerations underwrite a kind of ‘psychophysical fine-tuning’ argument in support of panpsychism, one that is reminiscent of cosmological fine-tuning arguments in favor of multiverse hypotheses.

We motivate five constraints on theorizing about sensory experience. We then propose a novel form of naturalistic intentionalism that succeeds where other theories fail by satisfying all of these constraints. On the proposed theory, which we call structure matching tracking intentionalism, brains states track determinables. Internal structural features of those states select determinates of those determinables for presentation in experience. We argue that this theory is distinctively well-positioned to both explain internal-phenomenal structural correlations and accord external features a role in fixing phenomenology. In addition, we use the theory to shed light on how one comes to experience “missing shades”.

Panpsychism claims that the vast majority of conscious subjects in our world are inanimate and physical. Ensemble explanations account for striking phenomena by placing them within an ensemble of outcomes, most of which are not striking. This paper develops an explanatory problem for panpsychism: panpsychism renders two appealing ensemble explanations unsatisfactory. Specifically, we argue that panpsychism renders unsatisfactory the multiverse explanation of why a universe supports life and the many-planets explanation of why a planet supports life.

Morality is intrapersonally permissive: cases abound in which an agent has more than one morally permitted option. In contrast, there is a dearth of cases in which an agent has more than one epistemically permitted response to her evidence. Given the structural parallels between morality and epistemology, why do sources of moral permissiveness fail to have parallel permissive effects in the epistemic domain? This asymmetry between morality and epistemology cries out for explanation. The paper's task is to offer an answer to that call. We explain the asymmetry by tracing moral permissiveness to two factors to which rationality is morally but not epistemically sensitive.

The chief motivation for epiphenomenalist dualism is its promise to solve dualism’s causal exclusion problem without inducing causal overdetermination or violations of the causal closure of the physical. This paper argues that epiphenomenalist dualism is itself susceptible to an exclusion problem. The problem exploits symmetries of determination and influence generated by a wide class of physical theories. Further, I argue that there is an interference effect between solving epiphenomenalist dualism's exclusion problem and using epiphenomenalist dualism as a solution to the causal exclusion problem. What emerges is an overlooked, empirically-motivated challenge to epiphenomenalist dualism.