The Doomsday Argument and the Simulation Argument

The Doomsday Argument and the Simulation Argument share certain structural features, and hence are often discussed together (Bostrom 2003, Are you living in a computer simulation, Philosophical Quarterly, 53:243–255; Aranyosi 2004, The Doomsday Simulation Argument. Or why isn’t the end nigh, and you’re not living in a simulation, http://philsci-archive.pitt.edu/190/; Richmond 2008, Doomsday, Bishop Ussher and simulated worlds, Ratio, 21:201–217; Bostrom and Kulczycki 2011 A patch for the Simulation Argument, Analysis, 71:54–61). Both are cases where reflecting on one’s location among a set of possibilities yields a counter-intuitive conclusion—in the first case that the end of humankind is closer than you initially thought, and in the second case that it is more likely than you initially thought that you are living in a computer simulation. Indeed, the two arguments do have some structural similarities. But there are also significant disanalogies between the two arguments, and I argue that these disanalogies mean that the Simulation Argument succeeds and the Doomsday Argument fails.     

Testing the Doomsday Argument

ABSTRACT Brandon Carter's anthropic principle reminds us that observers are most likely to find themselves in the spatiotemporal regions containing most of them. One should tend to prefer theories which make one's own observed spatiotemporal position fairly ordinary. This could much increase the estimated likelihood that our technological civilisation was not the very first in a universe which would include hugely many such civilisations. Similarly, which is the Carter-Leslie 'doomsday argument', it could much increase the estimated likelihood that you and I are not in the earliest 0.01%, for instance, of all humans who will ever have lived—as we would be if the human race survived for long even at its present size, let alone if it colonised the galaxy. With the aid of thought-experiments, the article defends this argument against many objections. Other thought-experiments suggest, though, that the argument is weaker if the world is radically indeterministic. In this case, it perhaps indicates only that we should not be highly confident in humankind's long survival, because high confidence would be equivalent to saying that any indeterminism would be unlikely to be relevant.     

The Doomsday Argument and the Number of Possible Observers

If the human race comes to an end relatively shortly, then we have been born at a fairly typical time in the history of humanity; if trillions of people eventually exist, then we have been born in the first surprisingly tiny fraction of all people. According to the 'doomsday argument' of Carter, Leslie, Gott and Nielsen, this means that the chance of a disaster which would obliterate humanity is much larger than usually thought. But treating possible observers in the same way as those who actually exist avoids this conclusion: our existence is more likely in a race which is long-lived, and this cancels out the doomsday argument, so that the chance of a disaster is only what one would ordinarily estimate.     

A Dilemma for the Doomsday Argument

I present a new case in which the Doomsday Argument (‘DA’) runs afoul of epistemic intuition much more strongly than before. This leads to a dilemma: in the new case either DA is committed to unacceptable counterintuitiveness and belief in miracles, or else it is irrelevant. I then explore under what conditions DA can escape this dilemma. The discussion turns on several issues that have not been much emphasised in previous work on DA: a concern that I label trumping; the degree of uncertainty about relevant probability estimates; and the exact sequence in which we integrate DA and empirical concerns. I conclude that only given a particular configuration of these factors might DA still be of interest.     

The Doomsday Argument without Knowledge of Birth Rank

The Carter–Leslie doomsday argument can be given in a situation where you do not know your birth rank, even approximately. This gives support to the refutation of the doomsday argument based on the self–indication assumption 'Finding that you exist gives you reason to think that there are many observers'.     

The Doomsday Argument Adam & Eve,UN++, and Quantum Joe

The Doomsday argument purports to show that the risk of the human species going extinct soon has been systematically underestimated. This argument has something in common with controversial forms of reasoning in other areas, including: game theoretic problems with imperfect recall, the methodology of cosmology, the epistemology of indexical belief, and the debate over so-called fine-tuning arguments for the design hypothesis. The common denominator is a certain premiss: the Self-Sampling Assumption. We present two strands of argument in favor of this assumption. Through a series of thought experiments we then investigate some bizarre prima facie consequences – backward causation, psychic powers, and an apparent conflict with the Principal Principle.     

A Contextualist Reply to the Direct Argument

The Direct Argument for the incompatibility of moral responsibility and determinism is designed to side-step complaints given by compatibilist critiques of the so-called Transfer Argument. I argue that while it represents an improvement over the Transfer Argument, it loses some of its plausibility when we reflect on some metalogical issues about normal modal modeling and the semantics of natural language. More specifically, the crucial principle on which the Direct Argument depends appears doubtful where context plays a role in evaluation of normative claims.     

The Paradox of Self–Consciousness Revisited

The so–called paradox of self–consciousness suggests that self–consciousness, understood as the capacity to think about oneself in a first–person way, cannot be explained. The author of the paradox contends that the only way to avert this result is by invoking the notion of nonconceptual first–person thought. This contention is rooted in adherence to the Linguistic Priority Principle, which dictates that pre–and nonlinguistic creatures lack concepts. I argue that the latter claim is dubious, and that the paradox of self–consciousness can be better disarmed by denying the dependence of first–person conceptual thought on first–person language.     

No Doomsday Argument without Knowledge of Birth Rank: a Defense of Bostrom

The Doomsday Argument says we should increase our subjective probability that Doomsday will occur once we take into account how many humans have lived before us. One objection to this conclusion is that we should accept the Self-Indication Assumption (SIA): Given the fact that you exist, you should (other things equal) favor hypotheses according to which many observers exist over hypotheses on which few observers exist. Nick Bostrom argues that we should not accept the SIA, because it can be used without knowledge of birth rank. Bradley Monton tries to construct a Doomsday Argument without knowledge of birth rank. I argue that Monton fails. The argument he constructs has implicit knowledge of birth rank and it is this knowledge that does the work. Furthermore, I argue that provided we dont have certain specific information about the future, the Doomsday Argument requires knowledge of birth rank.     

Reasonably Traditional: Self–Contradiction and Self–Reference in Alasdair MacIntyre's Account of Tradition–Based Rationality

Alasdair MacIntyre's account of tradition–based rationality has been the subject of much discussion, as well as the object of some recent charges of inconsistency. The author considers arguments by Jennifer Herdt, Peter Mehl, and John Haldane which attempt to show that MacIntyre's account of rationality is, in some way, inconsistent. It is argued that the various charges of inconsistency brought against MacIntyre by these critics can be understood as variations on two general types of criticism: (1) that MacIntyre's account of tradition–based rationality presents a picture of rationality with inconsistent internal elements, and (2) that MacIntyre, in the act of presenting his picture of rationality, makes the sort of claims to which his own account of rationality denies legitimacy, and thus MacIntyre's account is self–referentially incoherent. In response to criticisms of the first sort, it is argued that MacIntyre can further clarify or develop his position to take the current criticisms into account without altering the fundamental aspects of his picture of rationality. In response to the charge of self–referential incoherence, it is argued that the charge rests on a mistaken understanding of MacIntyre's position and of the nature of justification. In dealing with these arguments, the author hopes to not only vindicate MacIntyre's account of rationality against the charges of some of its recent critics, but also to shed some light on the nature of arguments both for and against relativism and historicism.     

Self–Deception, Motivation, and the Desire to Believe

In the debate over the nature of self–deception, "intentionalists" argue that self–deception requires an intention to deceive oneself, and "motivationists" argue that a desire, and not an intention, typically plays a crucial causal role in self–deception. Intentionalists have criticized motivationist views for ignoring what is distinctive about self–deception, and for failing to account for cases of "twisted" self–deception. I offer a new motivationist account whose distinctive element is the desire to believe. I argue that this account identifies what is common to cases of both "twisted" and "straight" self–deception, and that it captures what is distinctive about self–deception.     

Defending the Democratic Argument for Limitarianism: A Reply to Volacu and Dumitru

In this paper, I argue that limitarian policies are a good means to further political equality. Limitarianism, which is a view coined and defended by Robeyns (2017), is a partial view in distributive justice which claims that under non-ideal circumstances it is morally impermissible to be rich. In a recent paper, Volacu and Dumitru (2018) level two arguments against Robeyns’ Democratic Argument for limitarianism. The Democratic Argument states that limitarianism is called for given the undermining influence current inequalities in income and wealth have for the value of democracy and political equality. Volacu and Dumitru’s Incentive Objection holds that limitarianism places an excessive and inefficient burden on the rich in ensuring political equality. The Efficacy Objection holds that even if limitarianism limits excessive wealth it still fails to ensure the preservation of political equality. In this paper, I will argue that both of these objections fail, but on separate grounds. I argue that the Incentive objection fails because one could appeal to limitarian policies that are different from the ones discussed by Volacu and Dumitru and which escape the problem of reduced productivity. I argue against the Efficacy Objection that limitarian policies are a partial but highly valuable step towards establishing political equality, and that they can and should complement or be complemented by other strategies.

     

Reply to Nagasawa on the Inconsistency Objection to the Knowledge Argument

Yujin Nagasawa has recently defended Frank Jackson’s knowledge argument from the “inconsistency objection.” The objection claims that the premises of the knowledge argument are inconsistent with qualia epiphenomenalism. Nagasawa defends Jackson by showing that the objection mistakenly assumes a causal theory of phenomenal knowledge. I argue that although this defense might succeed against two versions of the inconsistency objection, mine is unaffected by Nagasawa’s argument, in which case the inconsistency in the knowledge argument remains.     

Hearing a Still-Ticking Bomb Argument: A Reply to Bufacchi and Arrigo

My aim in this paper is to demonstrate that the recent anti-Ticking Bomb argument offered by Bufacchi and Arrigo is unsuccessful. To adequately refute the Ticking Bomb strategy, I claim, requires carefully addressing both policy questions and questions involving exceptional conduct.