Intuitions as evidence in moral philosophy

Abstract

This thesis consists of two main section – each one of them offers an argument in favour of the evidential use of intuitions in moral philosophy. The aim is to defend the evidential use of moral intuitions. This presupposes that moral intuitions are commonly used as evidence (Cappelen’s Centrality Thesis) and that moral intuitions display the necessary credentials in order to be useful as evidence (reliability). Most recently the use of intuitions as evidence came under attack from two distinct sides. Cappelen (2012) presented an empirically based argument that it is false that intuitions were used as evidence in philosophy. He described the common perception of the central status of intuitions as evidence in philosophy as misguided and unfounded; challenging the discipline to provide an empirical argument to the contrary. The second recent challenge comes from a rather new field of research – experimental philosophy. The so-called negative programme of experimental moral philosophy tries to show by means of experiments that intuitions are sensitive to philosophically irrelevant factors. Such factors include ordering and framing, as well as cultural and demographical variables (gender, age, etc). By showing that moral intuitions are vulnerable to such morally arbitrary factors they try to undermine the use of intuitions as evidence by establishing their unreliability.

The first section of this thesis takes up Cappelen’s challenge to provide an argument for Centrality – the thesis that “Contemporary analytic philosophers rely on intuitions as evidence (or as a source of evidence) for philosophical theories” (Cappelen 2012, 3). I will do so by looking at Climenhaga’s (2017) attempt of addressing Cappelen’s challenge. I, initially, focus on Climenhaga’s account because it is instructive how it fails, which provides the foundation for my answer to Cappelen’s challenge. In the second part of this chapter I develop a more accurate account of how intuitions are used as evidence in philosophical practice, improving on Climenhaga’s account. I do so by suggesting that intuitings are used as source of evidence and intuited (propositional content of intuitings) are used as evidence. This proposal allows not only to solve many of the problems Climenhaga’s account is prone to but also allows to offer an explanation for a fourth fact of philosophical practice, which has not been available beforehand. In the final section of this chapter I address three anticipated challenges: Cappelen’s demand for direct empirical evidence, Climenhaga’s claim of evidential transitivity, and Machery’s argument to refocus our attention to the method of cases.

After having established that intuitions are used as evidence in philosophy affirming Centrality, and thus philosophers engaged in this practice should accept that intuitions are used as evidence, the remaining question is whether intuitions are a good source of evidence. This is one of my premises for my explanation of the first fact of philosophical practice. Only if intuitings are a good source of evidence, their us as such would be justifiable. The question of the quality of intuitings as a source of evidence is commonly phrased in terms of the reliability-challenge by the negative programme of experimental philosophy.

The second section takes up the Reliability Challenge of the negative programme of experimental moral philosophy, which consists of two mutually dependent arguments to challenge the use of moral intuitions as evidence. The first, is an empirical argument; the second a generalisation of the inductive base – both arguments together constitute the Reliability Challenge. In this section, I focus mainly on the first argument. The empirical argument seeks to establish by experimental means that most intuitions elicit by thought experiment vary unsystematically to a statistically significant extent and therefore intuitions are unreliable as evidence. I will analyse the underlying empirical findings, especially the experimental setup to ascertain the relevant data and the subsequently used statistical methods to analyse and interpret these findings. Initially, I will demonstrate how limited the actual supporting experimental evidence is for the conclusion of the empirical argument. Then, I will go on arguing, that even this limited empirical base is riddled with inaccuracies and flaws due to methodological decisions and misleading statistical analysis and associated statistical effects with the result that effects the purported consequences of experimental thought-experiments do not stand up to close scrutiny. I will investigate in detail 15 studies, which were all reported as having large effect sizes, meaning that they uncovered not only a statistically significant effect of morally arbitrary factors, but also a practical significant difference – supporting the negative programmes argumentative aim that moral intuitions are essentially unreliable as evidence. All 15 experiments were found to be fundamentally flawed in either questionnaire design or statistically interpretation. The empirical argument rests upon deeply distorted and restricted foundations and does not adequately reflect established philosophical methodology. Therefore, the Reliability challenge of the negative programme of experimental moral philosophy lost its empirical foundation and with that its argumentative bite.

It can be concluded in light of this thesis, that it is neither true that philosophers do not use intuitions as evidence – to the contrary we have good reasons to believe that the evidential use of intuitions in philosophical practice is characteristically and widespread. Moreover, there is no sufficient empirical evidence to support the claim that moral intuitions are substantially affected by morally arbitrary factors, thus, the Reliability Challenge is groundless. To the contrary, some experiments reported a resilience of strong intuitions to any morally arbitrary factors, supporting their reliability and by extension their use as evidence. Looking forward, experimental philosophy especially experimental moral philosophy could help to identify particularly vulnerable or weak intuitions which should be excluded or heavily discounted when used within the method of cases or the reflective equilibrium.