Martin Peterson

In this paper we shed new light on the Argument from Disagreement by putting it to test in a computer simulation. According to this argument widespread and persistent disagreement on ethical issues indicates that our moral opinions are not influenced by any moral facts, either because no such facts exist or because they are epistemically inaccessible or inefficacious for some other reason. Our simulation shows that if our moral opinions were influenced at least a little bit by moral facts, we would quickly have reached consensus, even if our moral opinions were affected by factors such as false authorities, external political shifts, and random processes. Therefore, since no such consensus has been reached, the simulation gives us increased reason to take seriously the Argument from Disagreement. Our conclusion is however not conclusive; the simulation also indicates what assumptions one has to make in order to reject the Argument from Disagreement. The simulation algorithm we use builds on the work of Hegselmann and Krause (J Artif Soc Social Simul 5(3); 2002, J Artif Soc Social Simul 9(3), 2006).

It is a natural assumption in mainstream epistemological theory that ascriptions of knowledge of a proposition p track strength of epistemic position vis-à-vis p. It is equally natural to assume that the strength of one’s epistemic position is maximally high in cases where p concerns a simple analytic truth. For instance, it seems reasonable to suppose that one’s epistemic position vis-à-vis “a cat is a cat” is harder to improve than one’s position vis-à-vis “a cat is on the mat”, and consequently, that the former is at least as unambiguous a case of knowledge as the latter. The current paper, however, presents empirical evidence which challenges this intuitive line of reasoning. Our study on the epistemic intuitions of hundreds of academic philosophers supports the idea that simple and uncontroversial analytic propositions are less likely to qualify as knowledge than empirical ones. We show that our results, though at odds with orthodox theories of knowledge in mainstream epistemology, can be explained in a way consistent with Wittgenstein’s remarks on ‘hinge propositions’ or with Stalnaker’s pragmatics of assertion. We then present and evaluate a number of lines of response mainstream theories of knowledge could appeal to in accommodating our results. Finally, we show how each line of response runs into some prima facie difficulties. Thus, our observed asymmetry between knowing “a cat is a cat” and knowing “a cat is on the mat” presents a puzzle which mainstream epistemology needs to resolve.

It is widely believed that consequentialists are committed to the claim that persons are mere containers for well-being. In this article I challenge this view by proposing a new version of consequentialism, according to which the identities of persons matter. The new theory, two-dimensional prioritarianism, is a natural extension of traditional prioritarianism. Two-dimensional prioritarianism holds that wellbeing matters more for persons who are at a low absolute level than for persons who are at a higher level and that it is worse to be deprived of a given number of units than it is good to gain the same number of units, even if the new distribution is a permutation of the original one. If a fixed amount of well-being is transferred from one person to another and then transferred back again, two-dimensional prioritarianism implies that it would have been better to preserve the status quo

Johansson and Rosenqvist reject our argument for the rational permissibility of pure time preferences. Johansson and Rosenqvist's main objection is that where two options, X and Y, have equal intrinsic value, there will be a reason to be indifferent between X and Y, and therefore a reason to not hold a PTP for X or Y. In this reply, we argue that if two options have equal intrinsic value, it does not follow that you have a reason to be indifferent. Rather, the two equally large intrinsic values cancel each other out, like two equal weights on kitchen scales.

Armchair philosophers have questioned the significance of recent work in experimental philosophy by pointing out that experiments have been conducted on laypeople and undergraduate students. To challenge a practice that relies on expert intuitions, so the armchair objection goes, one needs to demonstrate that expert intuitions rather than those of ordinary people are sensitive to contingent facts such as cultural, linguistic, socio-economic, or educational background. This article does exactly that. Based on two empirical studies on populations of 573 and 203 trained philosophers, respectively, it demonstrates that expert intuitions vary dramatically according to at least one contingent factor, namely, the linguistic background of the expert: philosophers make different intuitive judgments if their native language is English rather than Dutch, German, or Swedish. These findings cast doubt on the common armchair assumption that philosophical theories based on armchair intuitions are valid beyond the linguistic background against which they were developed

In this article I respond to comments and objections raised in the special issue on my book The Dimensions of Consequentialism. I defend my multi-dimensional consequentialist theory against a range of challenges articulated by Thomas Schmidt, Campbell Brown, Frances Howard-Snyder, Roger Crisp, Vuko Andric and Attila Tanyi, and Jan Gertken. My aim is to show that multi-dimensional consequentialism is, at least, a coherent and intuitively plausible alternative to one-dimensional theories such as utilitarianism, prioritarianism, and mainstream accounts of egalitarianism. I am very grateful to all contributors for reading my book so closely and for devoting time and intellectual energy to thinking about the pros and cons of multi-dimensional consequentialism

Peter Singer has famously argued that people living in affluent western countries are morally obligated to donate money to famine relief. The central premise in his argument is that, If it is in our power to prevent something bad from happening, without thereby sacrificing anything of comparable moral importance, we ought, morally, to do so. The present paper offers an argument to the effect that affluent people ought to support foreign aid projects based on a much weaker ethical premise. The new premise states that, If it is in our power to prevent something bad from happening, without thereby sacrificing anything of moral importance, we ought, morally, to do so. This premise, supplemented with a notion of final value drawing on Amartya Sen''s concept of freedom as capabilities and functionings, is conceived as a special version of a weak, egalitarian Pareto principle.