We administered the PhilPapers Survey, created by David Bourget & David Chalmers, which consists of 30 views on central philosophical topics (eg. epistemology, ethics, metaphysics, philosophy of mind, and philosophy of language) to a sample of professional philosophers (n = 314). We extended the PhilPapers survey to measure a number of psychological traits, such as personality, numeracy, well-being, lifestyle, and life experiences. We also included non-technical ‘translations’ of these views for eventual use in other populations.

We found limited to no support for the notion that personality or demographics predict philosophical views. We did, however, find that some psychological traits were predictive of philosophical views, even after strict correction for multiple comparisons. Findings include: higher interest in numeracy predicted physicalism, naturalism, and consequentialism; lower levels of well-being and higher levels of mental illness predicted hard determinism; using substances such as psychedelics and marijuana predicted non-realist and subjectivist views of morality and aesthetics; having had a transformative or self-transcendent experience predicted theism and idealism.

We discuss whether or not these empirical results have philosophical implications, while noting that 68% of our sample of professional philosophers indicated that such findings would indeed have philosophical value.

…In 2009, Bourget and Chalmers launched a study, the PhilPapers Survey, to answer the question, “What are the views of contemporary professional philosophers?” [Bourget & Chalmers2014]…The results of this survey are of general interest. Its findings include the frequencies of views across the 30 questions, correlations among the views, and correlations between the views and various demographic variables such as age, geographic location, and gender. A factor analysis was performed on the 30 views to determine whether they group according to underlying dimensions. The first factor, labeled “Anti-naturalism” by the authors, included libertarian notions of free will, non-physicalism about the mind, belief in God, non-naturalism, belief in the metaphysical possibility of philosophical Zombies, and the further fact view of personal identity. (Other factors included: “Objectivism/Platonism”, “Rationalism”, and “Externalism”). We made use of the Anti-Naturalism factor in the present study.

…3.3.1. factor analysis: Following Bourget & Chalmers2014, we performed Exploratory Factor Analysis. Bourget and Chalmers presented 7 factors but only interpreted the first few factors (Anti-Naturalism, Objectivism/Platonism, Rationalism, Anti-Realism, and Externalism). Notably, when computing the reliability (Cronbach’s alphas) of the factors reported by Bourget & Chalmers2014 using the variables that they used but in the new sample, we found that only the first factor (Anti-Naturalism) had adequate reliability (Cronbach’s Alpha >0.7), so interpreting the other factors should be done with caution. We also conducted an exploratory factor analysis in our data, following , by using the same sub-set of items that they selected to perform factor analysis on (30 items, one variable per philosophical view) and using the same rotation procedure that they did, Principal Component Analysis with a Varimax rotation. Parallel Analysis (PA) on this set of philosophical views suggested 6 factors (Figure 1). Analyses were conducted using the statistical software R (R Core Team2019).

We extracted two factors, Anti-Naturalism and Realism (Table 6), because factor solutions of 3 and above resulted in error factors due to their inadequate reliability. Also, the Scree plot suggests a two-factor solution. We then conducted the same analysis (using Varimax rotation) on the psychological trait variables at the behest of a reviewer. This item set included 39 single items as well as scale total variables, consisting of: demographics, personality, numeracy, well-being, life experiences, and lifestyle. Parallel Analysis suggested 8 factors (Figure 2).

We computed scale scores from an unweighted average of the items comprising each factor. The philosophical views factors correlated with one another to a moderate degree (r = 0.32, p = < 0.000), while the psychological trait factors were not associated with one another (r = 0.02, p = 0.703).

Philosophical View	PC 1: “Anti-Naturalism”	PC 2: “Realism”
Mind: Nonphysicalism	0.74
Meta-Philosophy: Non-Naturalism	0.63
God: Theism	0.59
Freewill: Libertarian	0.46
Meta-Ethics: Moral Realism		0.60
Abstract Objects: Platonism		0.50
Moral judgment: Cognitivism		0.49
External World: Realism		0.47
Aesthetic Value: Objective		0.43
Knowledge Claims: Invariantism		0.42
Laws of Nature: Hume		−0.44
Science: Anti-Realism		−0.50
Component Cronbach Alphas	α = 0.77	α = 0.71

Table: Table 6: Factor loadings of philosophical views. Factor loadings below 0.4 were not retained and are not shown. “Knowledge: Rationalism” loaded (marginally) on both factors so was dropped.

**Table 6**: *Factor loadings of philosophical views.* Factor loadings below 0.4 were not retained and are not shown. “Knowledge: Rationalism” loaded (marginally) on both factors so was dropped.
Philosophical View	PC 1: “Anti-Naturalism”	PC 2: Experiences
Life Satisfaction	0.76
Positive Emotion (ESAT)	0.71
Happiness	0.62
Personality: Neuroticism	−0.52
Loneliness	−0.59
Patient Health Questionnaire (PHQ)	−0.76
Negative Emotion (ESAT)	−0.81
Religious Experience		0.69
Self-Transcendent Experience—Unity		0.65
Spirituality		0.62
Transformative Experience		0.58
Meditation		0.56
Self-Transcendent Experience—Self-Loss		0.52
Religiosity		0.45
Component Cronbach Alphas	α = 0.80	α = 0.77

…4.1. Discussion of analysis of hypotheses: In general, we found quite limited support for our hypotheses regarding the tender-minded and tough-minded types described by William James, as we conceptualized and operationalized the distinction here. We found that those who endorse God: Theism were more Agreeable, as has been found to be the case in the normal population (Saroglou2002). We also found that the Anti-Naturalism factor was related to less Numeric Interest, though it is not clear how directly this measure relates to more analytical versus intuitive forms of thinking. Indeed, the strength of the association between interest in numerical information and a number of philosophical views is puzzling in a few cases, and is worthy of further study.

Offering some support of James’s distinction, we note that of the philosophical views that we measured that were mentioned in the tender/tough minded distinction—Knowledge: Rationalism, Freewill: Libertarian, and God: Theism on the one side, and Knowledge: Empiricism, non-libertarian notions of free-will, and Theism: Atheism on the other side were themselves inversely correlated. But only marginal support was found for the relationships between these clusters of philosophical views and the particular psychological traits that we measured. In addition to Agreeableness correlating with God: Theism, Free Will: No Free Will (hard determinism) was associated with lower Life Satisfaction and higher Depression/Anxiety,

although this was in the exploratory analysis. Taken together, this combination of findings could perhaps be seen to constitute some degree of “tender-mindedness.” Therefore, while our particular operationalizations relying on the Anti-Naturalism factor were largely not supported, James’s notion of the tough-minded and tender-minded types remains a live hypothesis—although certainly in a much more minimal way than we initially supposed.

We also found that the Normative Ethical view of Consequentialism is associated with more Numerical Interest, which comports well with the history of and some common intuitions surrounding consequentialism. However, we reiterate that we did not find evidence to support many of our other hypotheses. In particular, the Anti-Naturalism factor was largely unrelated to personality, well-being, and performance on the CRT in this sample of professional philosophers.

We acknowledge here the complexities that arise from drawing evidence from a null finding; absence of evidence is not evidence of absence in the null hypothesis testing paradigm.