Aurélien Allard

Do people have the intuition that free will and moral responsibility are compatible with determinism? To find out, experimental philosophers have presented participants with vignettes describing agents in deterministic universes and probed their intuitions about the free will and moral responsibility of these agents. However, these debates soon got embroiled around the difficulty of assessing whether participants correctly understood the vignettes and the concepts of determinism and free will and the extent to which different comprehension errors plagued participants’ answers. In this chapter, we clarify those debates by using the results of a brand new study (N = 772) on participants’ intuitions about free will. We introduce readers to correlations, regressions, multiple regressions, mediation analyses, and multiple mediation analyses through the use of structural equation modeling to show how different techniques may give different interpretations of folk intuitions on free will. We explain how to run these different analyses in R and provide detailed R code.

This graduate textbook provides a basic introduction to experimental philosophy (x-phi). In nine chapters, different methods and tools used in X-Phi are explained, spanning quantitative vignette studies, interactive experiments, corpus analysis, psycholinguistic experiments as well as qualitative interview studies. Each chapter introduces a specific experimental method by means of a case study in an easily accessible way and covers the whole research process from the development of a research question to the interpretation of the data.

Responding to recent concerns about the reliability of the published literature in psychology and other disciplines, we formed the X-Phi Replicability Project (XRP) to estimate the reproducibility of experimental philosophy (osf.io/dvkpr). Drawing on a representative sample of 40 x-phi studies published between 2003 and 2015, we enlisted 20 research teams across 8 countries to conduct a high-quality replication of each study in order to compare the results to the original published findings. We found that x-phi studies – as represented in our sample – successfully replicated about 70% of the time. We discuss possible reasons for this relatively high replication rate in the field of experimental philosophy and offer suggestions for best research practices going forward.

While psychologists and political scientists have long investigated issues of interest to philosophers, the development of political experimental philosophy has remained limited. This slow progress is surprising, given that political philosophers commonly acknowledge the relevance of empirical data for normative theorizing. In this chapter, we illustrate the importance of empirical data by outlining recent developments in three domains related to theories of justice, where empirical results reinforce or endanger popular philosophical theories. Our first showcase concerns the boundaries of the concept of fairness. While both libertarian thinkers and social egalitarians have united in rejecting the concept of natural injustice, we show that people do consider that unpreventable natural inequalities can be described as unfair. Second, we take the example of impartiality devices, such as the veil of ignorance or the idea of an impartial spectator, to show that such devices are efficient at shifting people’s intuitions in a more impartial manner. Third, we review empirical data on fairness intuitions to show that people conform to a pluralist theory of justice, valuing desert, needs-satisfaction, and equality at the same time. However, distribution according to desert enjoys a privileged position: people mostly care for the satisfaction of basic needs of deserving recipients, and people are willing to tolerate large inequalities in meritocratic contexts. The centrality of desert leads to dilemmas for mainstream egalitarian theorists, as theories that do not recognize the value of desert could fail to find support or legitimacy within the population.

abstract The moral value of distributive equality constitutes one of the most contentious debates in political philosophy. Following Frankfurt, many philosophers have claimed that the intuitive appeal of equality is illusory and that egalitarian intuitions are fundamentally intuitions about the importance of satisfying basic needs. According to this argument, our intuitions tell us that inequality ceases to matter once a certain threshold has been reached. Despite the widespread appeal to intuitions regarding this issue, few empirical studies have tried to assess whether Frankfurt and his followers are right in claiming the lack of intuitiveness of equality per se. In a series of three experiments, we show that experimental evidence does not allow us to settle the intuitiveness of each theory: laypeople are divided in the consideration of the respective importance of needs and equality. While our results do show that laypeople attach special importance to needs‐fulfilment, it also seems that they are divided when it comes to the importance they grant to equality once needs are fulfilled. No theory is unanimously backed by participants, and it seems that, fundamentally, divisions among philosophers reflect deep divisions among people.