1. Introduction
Understanding the relationship between Hume's philosophy and ancient versions of philosophical scepticism is a vexed task. Broadly speaking, there are both difficult historical and philosophical considerations that demand attention. How much knowledge did Hume actually have of ancient sceptical texts? Did he read those texts directly, or in translation, or did he learn about them from secondary sources?Footnote 1 Even if he was largely misinformed about ancient scepticism, is there an objective resemblance between Hume's considered views and ancient versions of scepticism? The view that Hume's scepticism is a version of Pyrrhonian scepticism, or at least close to it, has been influential in the history of reading Hume, even dating back to his contemporaries.Footnote 2 Despite the trend in recent decades to qualify or minimise Hume's scepticism, the view that Hume should be called a Pyrrhonist still finds vocal proponents, and the view certainly has much to recommend it, owing to the ‘very sceptical’ flavour of much of Hume's work.Footnote 3
The aim of the present paper is to offer an understanding of the relationship between Humeanism and Pyrrhonism that stresses their points of departure. I offer here objections against the arguments offered for seeing Hume as a Pyrrhonist, including the arguments offered by Fosl (Reference Fosl2020), Baxter (Reference Baxter, Machuca and Reed2018) and Palkoska (Reference Palkoska2012). I maintain that Hume reveals one of the shortcomings of Pyrrhonism, concerning the connection between suspension of judgement (epochê) and tranquillity (ataraxia). On my reading, the critical question that emerges from considering Humeanism alongside Pyrrhonism takes precedence: Hume is not only not a Pyrrhonist, but he in fact offers a persuasive critique of Pyrrhonism, one that we should accept today even if we do not accept Hume's broader metaphysics or theory of mind.
To be clear, I am targeting here the claim that there is some substantial, objective resemblance between Hume's views and Pyrrhonism.Footnote 4 I am targeting this claim because it is well-known that Hume betrays ignorance about historical Pyrrhonism in both A Treatise of Human Nature (Reference Hume1739–40) and An Enquiry Concerning Human Understanding (first ed. Reference Hume1748).Footnote 5 In particular, Hume treats the fact that one cannot live without beliefs as an objection to Pyrrhonism. Hume then advocates practising philosophy, and indeed, living life more generally, as a moderate or ‘mitigated’ sceptic,Footnote 6 displaying no awareness of Sextus's own account of how sceptics should live.Footnote 7
The present argument has two broad parts. First, I object to the main reasons offered for identifying Hume as a Pyrrhonist by bringing out the textual and philosophical problems for that reading. Second, I argue that Hume's tacit repudiation of the connection between epochê and ataraxia has non-historical philosophical value: Hume allows us to perceive a true objection to a key component of Pyrrhonism. In essence, Hume's objection makes us realise how implausible it is for tranquillity to be the product of radical scepticism.
While many scholars have concerned themselves with the dissimilarities between Humeanism and Pyrrhonism, Hume's dismantling of the connection between epochê and ataraxia has rarely been prioritised. In two of the most prominent treatments of Hume's Pyrrhonism, Garrett (Reference Garrett and Sinnot-Armstrong2004) and Olshewsky (Reference Olshewsky1991) aim to correct the Popkinian tradition by offering alternative understandings of Hume's response to sceptical results. For Olshewsky (Reference Olshewsky1991, p. 275 ff.), Hume is a Ciceronian ‘Academic’ sceptic, while for Garrett (Reference Garrett and Sinnot-Armstrong2004, p. 86–87), Hume is a mitigated sceptic who endorses the ‘title principle’ in response to sceptical doubt. To be sure, both Garrett and Olshewsky aim to vindicate Hume's rebuttal of Pyrrhonism in EHU 12, but without singling out a contrast between Hume and Sextus on tranquillity specifically.Footnote 8 Penelhum (Reference Penelhum2000) and Loeb (Reference Loeb2002; Reference Loeb1998) have devoted more attention to tranquillity than these authors, but they remain doubtful about whether Hume's stance on the issue is right. Penelhum says, ‘It seems to me that the effect of philosophical perplexity upon human nature is unlikely to be uniform, and that Hume may be right about this effect on some people and wrong about its effect on others’ (Reference Penelhum2000, p. 188). I take a firmer stance than this. In what follows, I offer an explication of Hume's response to epochê that allows us to see the shortcomings of Sextus's view. Furthermore, I explicate the differences between Humeanism and Pyrrhonism while leaving open the possibility that Hume is an irredeemably sceptical philosopher. My argument makes no appeal to the title principle to circumscribe Hume's scepticism nor to the ‘usefulness and agreeableness’ reading of Hume's epistemology advocated by Ridge (Reference Ridge2003), Owen (Reference Owen1999), and others. In this regard, the present paper resists the trend of qualifying Hume's scepticism or subsuming it under his experimental philosophical methodology.
In the next section, I outline Sextus Empiricus's description of Pyrrhonism given at the start of Book I of his Outlines of Scepticism, before addressing the reasons that have been put forward for reading Hume as a Pyrrhonist.
2. Pyrrhonism and Humeanism
2.1 An Outline of Pyrrhonism
Sextus offers a summary of Pyrrhonism very early on in his Outlines under the heading ‘What is Scepticism?’. He describes it not as a set of doctrines, but as the ability to bring about tranquillity in a particular way:
Scepticism is an ability to set out oppositions among things which appear and are thought of in any way at all, an ability by which, because of the equipollence in the opposed accounts, we come first to suspension of judgement and afterwards to tranquillity (PH I.8).Footnote 9
The term ‘equipollence’ (isostheneia) describes that feature of states of affairs wherein different but equally convincing arguments, accounts, or presentations, conflict.Footnote 10 Sextus defines ‘equipollence’ directly as ‘equality with regard to being convincing or unconvincing’,Footnote 11 and it represents the Pyrrhonist's general motivation for adopting the sceptical outlook.Footnote 12 Most of the specific illustrations of sceptical considerations that Sextus runs through (including the ‘ten modes’ that are said to have originated with Aenesidemus of Cnossos, from the first century BCE) invoke the phenomenon of equipollence, most often with reference to sensory appearances. One classic example of an appeal to equipollence is the case of a tower that looks round from a distance but looks square up close (PH I.32). Sextus offers a myriad of other examples drawn from differences in perception between humans and animals (PH I.40–52), differences in perception amongst different people (PH I.79–87), and differences in both perception and opinion for the same person in different circumstances (PH I.100–113) to name a few.
The outcome of perceiving equipollence for the Pyrrhonist is suspension of judgement (epochê). This is that doxastic stance whereby one neither affirms nor denies the veridicality of an appearance, account, presentation, etc. What is distinctive about the Pyrrhonian application of epochê is the wide scope of things towards which they adopt this stance. For a Pyrrhonist, it is not merely that some particular types of investigation are unsuccessful at reaching the truth, or that some specific domains of human knowledge are empty. They insist, rather, that we can never hold one particular belief or appearance to be more veridical than not. Pyrrhonists especially shun all ‘philosophical investigations’ into the true natures of things, and, in tune with this, the large bulk of the Outlines is dedicated to rebuffing a range of philosophical theories and schools (PH I.1, 12–15).
The question that immediately arises from the Pyrrhonist's commitment to radical epochê is how they are supposed to live their lives. Sextus tackles this question head on in the Outlines, but much debate has surrounded fleshing out the details of his view – exemplified by the exchanges between Michael Frede and Myles Burnyeat, collected in their jointly edited The Original Sceptics: A Controversy (Reference Burnyeat and Frede1997). Burnyeat's view is that Pyrrhonists give their assent only to propositions of the form, ‘It appears to be the case that …’, but Frede sees the Pyrrhonists as assenting to all kinds of propositions but offering only a qualified, tentative version of assent itself. I will not take a stand on this issue here, but it should be noted that Baxter's (Reference Baxter, Machuca and Reed2018; Reference Baxter2008) Pyrrhonian reading of Hume utilises Frede's interpretation of Pyrrhonian assent. Common to both Burnyeat and Frede's readings is that Pyrrhonists defend themselves from the charge that they suffer inactivity (the ‘apraxia’ objection) by claiming that whatever is necessary for living and acting in the world is not what they forego. Sextus expands on how this is possible when describing his so-called ‘fourfold’ observances:
Thus, attending to what is apparent, we live in accordance with everyday observances, without holding opinions – for we are not able to be utterly inactive. These everyday observances seem to be fourfold, and to consist in guidance by nature, necessitation by feelings, handing down of laws and customs, and teachings of kinds of expertise (PH I.23).
This passage continues with Sextus illustrating each of the four aspects of everyday observances. I have added emphases and numbering to the following for clarity:
[1] By nature's guidance we are naturally capable of perceiving and thinking. [2] By the necessitation of feelings, hunger conducts us to food and thirst to drink. [3] By the handing down of customs and laws, we accept, from an everyday point of view, that piety is good and impiety bad. [4] By teaching of kinds of expertise we are not inactive in those which we accept. (PH I.23–4)
This passage serves a dual purpose: to explain how the sceptic lives, and to defend the sceptic from the charge of disingenuousness (think: what gives the sceptic the right to speak or argue, or to eat or drink, at all?). Sextus claims that sceptics can accept truisms that are forced on them by cultural influence and, startlingly, that they can even pursue professions (Sextus himself was a medical doctor). Even more, though, living according to this fourfold method offers the unique path to tranquillity (PH, I.26–30). This claim would have likely goaded the Pyrrhonists's contemporary opponents, since the Stoics and Epicureans offered their respective philosophies as the best way of living, even if they did not identify ataraxia specifically as the goal.Footnote 13 It is worth stressing that Sextus maintains that his account of how we can be led by nature to act in certain ways does not compromise the Pyrrhonian condemnation of philosophical investigations, investigations which Sextus characterises as involving ‘unclear’ matters (PH, I.13, 16).
After wrapping up his description of the aim of scepticism at PH I.25–30, Sextus moves on to describe the particular modes by which Pyrrhonists come to epochê (the rest of Book I and the whole of Books II and III concern Pyrrhonism in opposition to particular philosophical theories and schools). The following summary emerges: Pyrrhonism is the adoption of radical epochê, which is motivated by equipollence, and which purportedly leads to ataraxia. Suspending belief is a common sceptical trope, so what truly makes Pyrrhonism stand out amongst the different varieties of scepticism in the history of philosophy are equipollence and the connection between epochê and ataraxia. The scholarship on ancient philosophy confirms this, as Gisela Striker (Reference Striker and Bett2010) has shown that the commitment to epochê resulting in ataraxia is precisely what distinguishes Pyrrhonism from ancient Academic scepticism (the scepticism of members of Plato's Academy), since the Academics were as equally radical as the later Pyrrhonists.Footnote 14
2.2 The Pyrrhonist Reading of Hume
The starting point for understanding the issue of Hume's alleged Pyrrhonism is to see just how much Hume's overt descriptions of Pyrrhonism miss the mark. Advocates of the Pyrrhonist reading of Hume have not be troubled by his apparent ignorance of Pyrrhonism, because, going back to Popkin (Reference Popkin1951), their view has always been that Hume's position objectively resembles Pyrrhonism even if Hume himself did not recognise this.Footnote 15
Hume never straightforwardly defines Pyrrhonism, but his general understanding of it in EHU 12 is simple enough to glean.Footnote 16 Hume opens EHU 12 by noting an oddity, namely, that the sceptic is a feared and calumniated figure that seems to have no concrete existence. Hume finds that he has simply never encountered ‘a man, who had no opinion or principle concerning any subject’ (EHU 12.2, SBN 149). Prompted by this consideration, Hume sets himself the task of answering the following question: how far is it possible to be a sceptic? That is, how far can we push ‘principles of doubt and uncertainty?’ (ibid.). In the following, we see that Hume considers Pyrrhonism to be a philosophical outlook that pushes doubt and uncertainty very far indeed:
The great subverter of Pyrrhonism or the excessive principles of scepticism, is action, and employment, and the occupations of common life. These principles may flourish and triumph in the schools; where it is, indeed, difficult, if not impossible, to refute them. But as soon as they leave the shade … [they] vanish like smoke, and leave the most determined sceptic in the same condition as other mortals. (EHU 12.21, SBN 159. Added emphasis)
For Hume, Pyrrhonism is the ‘excessive’ variety of scepticism that stands at odds with ‘common life’. His view is that Pyrrhonism can be entertained in the study, but it cannot be sustained outside of it (this same understanding of Pyrrhonism is repeated at EHU 12.23, which will be looked at in Section 4).
The Pyrrhonist reading of Hume interprets his treatment of scepticism as follows: Hume explicates sceptical arguments that he considers irrefutable and then adopts the life and philosophical attitudes of a radical sceptic. It is easy to get lost in the details and there are many aspects of Humeanism and Pyrrhonism that we can draw comparisons between (in addition to Hume's overt remarks on scepticism, we can look at his epistemology more generally, not to mention his wider theory of mind and the myriad of things Sextus and other Pyrrhonists have had to say). Fundamentally, though, Fosl, Baxter, and others all hold that we ought to call Hume a Pyrrhonist and that, at the very least, the similarities between Hume and Pyrrhonism are more illuminating than the differences. I hold that the opposite is true.
Baxter (Reference Baxter, Machuca and Reed2018; Reference Baxter2008) maintains that Hume responds to his own sceptical doubts by giving only passive acquiescence to beliefs and that he extends the traditional Pyrrhonian view by acquiescing even in philosophical investigations (Reference Baxter2008, p. 390). Baxter unpacks ‘passive acquiescence’ by appealing to the Pyrrhonian fourfold method of assenting to appearances from PH I.23–4, and with specific reference to Michael Frede's reading of Pyrrhonism.Footnote 17 While Sextus argued against a multitude of different schools of philosophy, Hume, supposedly, wanted to be a Pyrrhonist while still pursuing his experimentally informed ‘science of man’ (T 1.4.7.14, SBN 273). Baxter sees Hume as offering passive acquiescence even in philosophy and therefore calls him a ‘Pyrrhonian Empiricist’ (Baxter Reference Baxter2008, p. 14). Palkoska's (Reference Palkoska2012) view is very similar to Baxter's, as he offers a reading that centres on Hume's theory of belief, and he appeals to an even wider range of texts to support the Pyrrhonian reading of Hume (drawing largely from T 1.3 and T 1.4.7). Palkoska argues that the appearances to which Pyrrhonists give non-dogmatic assent are analogous to Humean beliefs because they both: (i) are not determined by the will (T 1.3.13.19, SBN 153–4; PH I.19), and (ii) are sufficient for guiding action (T 1.3.7.7, SBN 269; EHU 5.12, SBN 49–50; PH I.21). Admittedly, Hume's responses to sceptical doubt in T 1.4.7 and EHU 12 (and other places – notably T 1.4.1.7–8, SBN 183–4 and T 1.4.2.57, SBN 218) often do seem like appeals to the fact that we must continue to live and breathe in the face of scepticism. This point props up much of what Palkoska and others have to say.
Ribeiro (Reference Ribeiro2009) has deftly illuminated how Hume stops short of offering any normative response to the sceptical problems that he raises. Ribeiro insists on the fact that particular beliefs being irresistible and deeply ingrained in human nature does not mean those beliefs gain any epistemic merit (Ribeiro Reference Ribeiro2009, pp. 22, 26). According to Ribeiro, this very point is what Thomas Reid missed in his appeal to common sense first principles and what Descartes successfully recognised in his demand for more than psychological conviction for his beliefs at the start of his Meditations (Ribeiro Reference Ribeiro2009, p. 26). Ribeiro leans on Hume's response to the scepticism in EHU 12 to support his Pyrrhonian reading of Hume, utilising more than once Hume's line that the instinct that leads us to reason inductively, ‘like other instincts, may be fallacious and deceitful’ (EHU 12.22, SBN 159).
Fosl, Baxter, Palkoska, and Ribeiro each tap into a long tradition of Hume scholarship, stretching back to the immediate reception of Hume's philosophy.Footnote 18 I find the Pyrrhonian reading of Hume, however, highly flawed, and not for reasons drawn from the arguments for anti-sceptical readings of Hume's philosophy. I hold that even if we read Hume sceptically, there is still no good case for reading him as a Pyrrhonist specifically. I turn now to my reasons for this.
3. Why Hume is Not a Pyrrhonist
I have outlined Pyrrhonism as the adoption of radical epochê, which is motivated by isostheneia, and which purportedly leads to ataraxia. Hume does indeed flirt with the idea of radical suspension of belief in both the Treatise and Enquiry, and Baxter and others certainly have much to exploit here. In the Treatise, Hume plainly states, ‘I am ready to reject all belief and reasoning, and can look upon no opinion even as more probable or likely than another’ (T 1.4.7.8, SBN 265). While ‘reject all belief’ betrays Hume's ignorance of the distinction between dogmatic affirmation and passive acquiescence, the Baxterian reading of Hume's scepticism does indeed read him as seeing ‘no opinion even as more probable or likely than another’. Baxter holds that Hume offered mere passive acquiescence to everything that Sextus did plus to theoretical matters. Before we consider this issue, I will first turn to the notion of equipollence (isostheneia) in Hume's philosophy, for one of the reasons I consider Humeanism and Pyrrhonism opposed systems is that Hume's scepticism is not motivated by equipollence.Footnote 19
Hume's sceptical strategy does not involve appealing to conflicting appearances or to the equal weight of evidence for competing claims. The theme that pervades Hume's arguments for scepticism is the establishment of mistrust of the mind's faculties. The difference may seem subtle, but I hope that it is clear enough: it is not that we have two equal bodies of evidence for given claims that leads us to scepticism, but rather, we can show that the faculties that generate beliefs either are, or may very well be, fallacious. The sceptical considerations in EHU 12 begin with two ‘profound arguments against the senses’ (EHU 12.6, SBN 151), which are also called two ‘objections’ (EHU 12.16, SBN 155) to the evidence of sense (these are two distinct objections that establish the unreliability of the senses for Hume; they are not two equal and opposed accounts). Hume then turns to the faculty of ‘reason’, and it is under this heading that Hume offers both sceptical objections to ‘abstract’ reasonings and his scepticism concerning ‘matters of fact’, the latter of which he supports by citing his theory of induction. Hume's theory of induction, in fact, offers perhaps the best illustration of the point at hand: it is the mere possibility of error, not the clash of competing appearances, that motivates scepticism about inferences from the past to the future.Footnote 20 Further, the unifying theme of Hume's sceptical crisis at T 1.4.7 is the unreliability of the imagination – the faculty that operates via the association of ideas (T 1.3.9.2, SBN 107). This operation is a ‘trivial’ process in Hume's eyes, but, regrettably, the ‘memory, senses, and understanding’ are all founded on it (T 1.4.7.3, SBN 265).Footnote 21 Hume began the Treatise as an investigation into the mind's faculties in order to illuminate their operations, but the dramatic turn at T 1.4.7 is brought about because his investigation has led him to distrust those very faculties.Footnote 22
This is not to say that the theme of conflict is not present in Hume's texts. It is clearly prevalent in certain places, especially in T 1.4.7.Footnote 23 But this conflict is generally an internal, mental conflict that results from the undermining of the faculties, rather than a conflict of competing accounts. This difference in sceptical strategies between Hume and Pyrrhonism and its relevance for the question of whether Hume can be called a Pyrrhonist has, in my eyes, been a neglected point in the literature.Footnote 24
But we should turn now to an even weightier issue, namely, Hume's attitude towards radical epochê. Does Hume really endorse this stance when it comes to the epistemic assessment of our beliefs, as the Pyrrhonian reading holds? Here we enter the most hotly contested area of Hume scholarship – reading Hume's response to the sceptical problems he raises in T 1.4.7 and EHU 12. There is a wide diversity of readings of Hume's sceptical crisis. Some commentators maintain that the crisis is not genuine and that it serves a rhetorical purpose.Footnote 25 Other positions include: seeing Hume as offering a robust, normative response to scepticism; seeing Hume as fundamentally and irredeemably sceptical; and seeing Hume as torn and ambivalent, as if there is a difference between what Hume wants to achieve and what he is entitled to achieve.Footnote 26 I do not have the space here to offer a full reading of either T 1.4.7 or EHU 12, but I will briefly state why I do not think those texts support the Pyrrhonian reading of Hume. Simply, while paragraphs T 1.4.7.8 and EHU 12.22 considered in themselves support reading Hume as endorsing radical epochê, those passages are not the final word in their respective texts and Hume plainly mitigates the sceptical attitude that he expresses therein. In T 1.4.7.9, for instance, Hume allows that ‘nature herself suffices’ to dispel his doubts, and he famously plays a game of back-gammon that transforms his outlook.Footnote 27 There are several more stages to the sceptical crisis in T 1.4.7, including a slow return to philosophy that, strikingly, features some distinctly epistemic language: Hume says that his science of man will contribute to ‘the advancement of knowledge’ and produce ‘assurance’ on philosophical matters (T 1.4.7.14, SBN 273). In the Enquiry, Hume advocates a ‘mitigated’ version of scepticism that includes a call to epistemic modesty and that allows us to see ‘what are the proper subjects of science and enquiry’ (EHU 12.6, SBN 183). To be clear, I do not think that these facts tell decisively against any overall sceptical reading of Hume. But it is a problem for the Pyrrhonian reading of Hume that T 1.4.7.8 and EHU 12.22 are clearly only stages in Hume's extended sceptical reflections. This gives us reason to doubt that Hume endorses radical epochê.
An even more severe problem for the Pyrrhonian reading of Hume still looms. Suppose the Baxterian reading of T 1.4.7 and EHU 12 were right. Would this be enough to make Hume a Pyrrhonist? I suggest not, given how essential Sextus finds the disavowal of opinions on theoretical matters and how he repeats that disavowal in different places in the Outlines.Footnote 28 Sextus has the following to say about practising both science and philosophy:
We do not study natural science in order to make assertions with firm conviction about any of the matters on which scientific beliefs are held. But we do touch on natural science in order to be able to oppose to every account an equal account, and for the sake of tranquillity. This is also the spirit in which we approach the logical and ethical parts of what they call philosophy. (PH I.18. Added emphasis)
Sextus is telling us here that the Pyrrhonists engage in both science and philosophy only in order to better display equipollence to their opponents and with the (non-dogmatic) aim of gaining tranquillity. That they entirely reject ‘firm conviction’ in philosophy and science sets them apart from Hume. Hume finds the need to have opinions on philosophical topics, including the following:
I am uneasy to think I approve of one object, and disapprove of another; call one thing beautiful, and another deform'd; decide concerning truth and falshood [sic], reason and folly, without knowing upon what principles I proceed. […] I feel an ambition to arise in me of contributing to the instruction of mankind […]. (T 1.4.7.12, SBN 271)
Indeed, Hume does not just feel a general ambition to contribute to the instruction of mankind, but he recommends one specific philosophical project – the experimental investigation of the human nature – as better suited to this than others:
But were these [speculative] hypotheses once remov'd, we might hope to establish a system or set of opinions, which if not true (for that, perhaps, is too much to be hop'd for) might at least be satisfactory to the human mind, and might stand the test of the most critical examination. Nor shou'd we despair of attaining this end […]. Human Nature is the only science of man; and yet has been hitherto the most neglected. ’Twill be sufficient for me, if I can bring it a little more into fashion […]. (T 1.4.7.14, SBN 272–3)
Hume's recommendation in this passage contravenes the Pyrrhonian rule of seeing all systems of philosophy as equally devoid of justification. While Hume does indeed express his scepticism in this passage (opting for ‘satisfactory to the human mind’ as a goal, in explicit contrast to truth), he still endorses a particular kind of philosophy, which is enough to disqualify him as a Pyrrhonist.
A further illustration of the Pyrrhonian rejection of philosophy can be seen in Sextus's comments on Plato, which he makes when commenting on Academic scepticism. For Sextus, it is enough for Plato to have had any philosophical opinions for him to count as a non-sceptic. Sextus states that, when making assertions about the existence of Forms or about a virtuous life being preferable to a vicious life: ‘if he [Plato] assents to these things as being really so, he is holding beliefs; and if he commits himself to them as being more plausible, he has abandoned the distinctive character of Scepticism’ (PH I.222). If Hume considers some opinions within the science of man to be more plausible than others, then Sextus's complaint about Plato will apply to Hume.Footnote 29
As mentioned, Fosl (Reference Fosl2020) takes quite a different approach to Baxter when arguing for a Pyrrhonian reading of Hume. Fosl draws a wide range of parallels and analogies between Pyrrhonism and Humeanism. At the heart of Fosl's view is that Hume both understood and endorsed the tradition of Pyrrhonian philosophy. Hume actively hid his Pyrrhonism, Fosl holds, so as to avoid the social and legal retribution he would have faced. I am doubtful of these claims because I find that even if Hume wanted to conceal his Pyrrhonism he still would not have offered such a flatfooted understanding of it in EHU 12. In that section, Hume evidently fails to grasp what purpose the Pyrrhonist could possibly have in mind: ‘We need only ask such a sceptic, What his meaning is? And what he proposes by all these curious researches? […] a Pyrrhonian cannot expect, that his philosophy will have any constant influence on the mind…’ (EHU 12.23, SBN 159–60. Original emphasis). But these rhetorical questions are answered on the very first pages of Sextus's Outlines. I find it implausible that Hume would have expressed his objections to Pyrrhonism this way, even if those objections were disingenuous. The consensus in Hume scholarship has been that Hume does indeed miss the mark when describing Pyrrhonism in EHU 12, and then the debate usually turns to what I call the ‘objective resemblance thesis’. Fosl takes a different approach when arguing for a Pyrrhonian reading of Hume, but it is one that I am wary of.
Given that I have opposed the Pyrrhonian reading of Hume so strongly, a natural question is, how do I read the relationship between Hume and Academic scepticism? Clearly, EHU 12 reflects some affinity between Hume and Academic scepticism, and Fosl even reads Hume as ultimately combining Pyrrhonism with Clitomachus's version of Academic scepticism.Footnote 30 To address this, I would first take a step back and observe that the key to reading Hume's scepticism in EHU 12 is grasping how excessive scepticism leads to mitigated scepticism – or, in other words, how realising the force of what Hume calls ‘Pyrrhonism’ leads to what Hume calls ‘Academic scepticism’. I consider accounting for this transition to be critical to reading Hume's scepticism as a whole, especially since the case for reading such a transition in Treatise 1.4.7 is strong.Footnote 31 I am open to there being informative parallels between a reading of Hume and Academic scepticism – but it is not immediately clear how the transition from extreme to mitigated scepticism would map onto the philosophies of the central figures of Academic scepticism, such as Cicero and Clitomachus. Perhaps it will turn out that Hume's scepticism is too unique and original to be identified too closely with any of the ancient schools of scepticism. There is a need for further research here.
I move on now to articulating the reasons why we should prioritise a critical point that emerges from considering Humeanism alongside Pyrrhonism.
4. Epochê, Ataraxia, and Hume's Sceptical Crisis
4.1 The Pyrrhonists's ‘Miserable Existence’
In the Enquiry, Hume provides a reductio ad absurdum against Pyrrhonism. Hume is no fan of either Stoicism or Epicureanism, but he admits that they can have a lasting influence on one's life.Footnote 32 The same cannot be said for Pyrrhonism:
A Stoic or Epicurean displays principles, which may not only be durable, but which have an effect on conduct and behaviour. But a Pyrrhonian cannot expect, that his philosophy will have any constant influence on the mind: Or if it had, that its influence would be beneficial to society. On the contrary, he must acknowledge, if he will acknowledge any thing, that all human life must perish, were his principles universally and steadily to prevail. All discourse, all action would immediately cease; and men remain in a total lethargy, till the necessities of nature, unsatisfied, put an end to their miserable existence. (EHU 12.23, SBN 160)
Earlier in the same paragraph, Hume identified ‘the chief and most confounding objection to excessive scepticism’ as its impracticality (EHU 12.23, SBN 159. Original emphasis). Hume says that ‘no durable good can ever result from it; while it remains in its full force and vigour’ (ibid.). Hume has two thoughts in mind: excessive doubt is impermanent and if it were permanent, it would have destructive results. I find this second point particularly incisive. If Hume's objection to Pyrrhonism were only that we must have beliefs to act, then this would be an uninteresting objection indeed. It would, after all, be directly countered by Sextus's response to the apraxia objection, where he describes the fourfold observances (PH I.23–4). But, by entertaining what the Pyrrhonist's life might in fact look like, Hume transforms his objection into a refutation of the Pyrrhonist's claim to enjoy tranquillity in virtue of epochê. And the point he makes applies even when we understand Pyrrhonism with more nuance than Hume did: Hume does not insist that Pyrrhonism is impossible, but that it is miserable. Although Hume never uses the terms ‘tranquillity’ or ‘suspension of judgement’, the just-quoted passage reveals that Hume holds that the following would happen if Pyrrhonism were ‘universally and steadily to prevail’:
(1) Humans would remain in lethargy.
(2) All discourse would end.
(3) All action would end.
(4) Human life would perish.
Hume's justification for making these claims comes at the same time that he describes why, in fact, they do not come about. Simply, our human nature ensures that we must live. The passage continues:
It is true; so fatal an event [as (1)–(4)] is very little to be dreaded. Nature is always too strong for principle. And though a Pyrrhonian may throw himself or others into a momentary amazement and confusion by his profound reasonings; the first and most trivial event in life will put to flight all his doubts and scruples […]. (EHU 12.23, SBN 159–60)
We cannot be Pyrrhonists permanently, and, if we could, we would be in a dire situation. This is a far cry from Sextus's view that radical epochê is both possible and the unique path to tranquillity. Admittedly, Hume leaves his readers the task of unpacking exactly why all this is the case, and his reference to ‘Nature’ is fairly handwavy. At the same time, though, Hume is not merely offering the flatfooted view that belief is a necessary condition for action. Hume is not even saying here that Pyrrhonism is absolutely impossible, since he indulges the idea that a Pyrrhonist may momentarily amaze and confuse others. But any effects of Pyrrhonism going beyond this momentary amazement can lead only to a ‘miserable existence’ (EHU 12.23, SBN 160).
Proponents of the Pyrrhonian reading of Hume may claim that the repudiation of Pyrrhonism in EHU 12 is a red herring. Their objection is that Hume only thought Pyrrhonism was unliveable because he was unacquainted with their notion of passive acquiescence and with their fourfold explanation of how the Pyrrhonist lives. Indeed, they may well insist that EHU 12.23 is redolent of Sextus's fourfold method, since Hume cites the influence of ‘nature’ there and Sextus refers to ‘guidance by nature’. As I see it, the situation is as follows. Hume is at least talking about radical epochê in EHU 12 – that is to say, his object is excessive scepticism. What is at issue is whether Hume's objection to Pyrrhonism is only made valid by ignoring the supplementary aspect of Pyrrhonism, that is, its explanation of how the Pyrrhonist lives. I think Hume that was not aware of this explanation and the text does not directly speak to it, so it will always be easy to disregard Hume's stated view. But I think we can do better. I hold that we can read Hume as offering a view on the human response to sceptical doubt. What I concede is that the Enquiry is not Hume's strongest statement on the issue. I imagine a defender of the Pyrrhonian reading insisting that Pyrrhonists would not ‘remain in lethargy’ if they followed the fourfold method. However, I think Hume's sceptical crisis in the Treatise offers an even richer account of Hume's rejection of Pyrrhonism. This is because, in the Treatise, epochê is no longer treated hypothetically, since we see Hume directly express a personal, if momentary, desire to suspend belief on every topic.
4.2 Existential Questions in Hume's Crisis in the Treatise
At the height of Hume's sceptical crisis in the Treatise, he says that sceptical worries have so heated his brain that they inspire him to see ‘no opinion even as more probable or more likely than another’ (T 1.4.7.8, SBN 269). He asks himself a number of questions that, at once, express his uncertainty and his angst:
Where am I, or what? From what causes do I derive my existence, and to what condition shall I return? Whose favour shall I court, and whose anger must I dread? What beings surround me? and on whom have I any influence, or who have any influence on me? (T 1.4.7.8, SBN 269)
In case there is any doubt about Hume's tone when registering these questions, the rest of the paragraph continues:
I am confounded with all these questions, and begin to fancy myself in the most deplorable condition imaginable, inviron'd with the deepest darkness, and utterly depriv'd of the use of every member and faculty. (T 1.4.7.8, SBN 268–9)
According to a Pyrrhonian sceptic, Hume ought to have found his lack of firm opinion liberating (cf. PH I.28). Clearly, though, Hume feels that by having established sweeping sceptical doubts he has entered a state of ‘darkness’ and has been deprived of his very faculties. Hume had earlier said that the faculty of reason ‘must be consider'd as a kind of cause, of which truth is the natural effect’ (T 1.4.1.1, SBN 180). This innocent confidence is now gone. Hume has shown how suspension of belief can undermine our confidence in basic questions about who we are and our ability to manipulate the world, questions for which it is naturally unsettling to feel uncertain about. This is a point that Hume backs up elsewhere in the Treatise, including when he explains the relationship between certainty and the direct passion of fear.Footnote 33
Now, recall that the objection to Hume's repudiation of Pyrrhonism in the Enquiry is that it fails if we bring the Pyrrhonist's fourfold method into the picture. Let's cast a critical eye over this. Perhaps passively acquiescing to a belief in tables or chairs while officially suspending belief about those things leaves us in a neutral position – one that is neither pleasant nor unpleasant – but what about beliefs more intimately related to our identity and to our place and purpose in society? A sense of social alienation rings strongly throughout T 1.4.7. We see this at T 1.4.7.8 and even earlier when Hume bemoans the fact that sceptical reflections have separated him from his fellow man: ‘Fain wou'd I run into the crowd for shelter and warmth; but cannot prevail with myself to mix with such deformity. I call upon others to join me, in order to make a company apart; but no one will hearken me’ (T 1.4.7.2, SBN 264). A host of ideas coalesce in T 1.4.7 to make Hume feel detached from his fellow man, and his lack of assurance about himself and about what beings surround him is central to this. This is incompatible with the Pyrrhonian view on the effects of scepticism.
The upshot of comparing Sextus and Hume on tranquillity, then, is that we can see how Sextus's view is only persuasive given a carefully selected set of examples. Consider Sextus's explanation of how the Pyrrhonist avoids disturbances in Book III of the Outlines. There, Sextus concludes the section titled ‘Is anything by nature good, bad or indifferent?’ by explaining the advantage that the Pyrrhonists gain from suspending judgement on the moral value of objects. Recalling his overview given at the start of Book I, Sextus refers to the way in which Pyrrhonists are affected by feelings forced on them by nature but then says that these feelings are ‘moderate’ compared to those of the non-sceptics (T 1.4.7.2, SBN 264). He even makes the remarkable claim that having an opinion about something being bad is ‘worse than actually feeling it’ (ibid.). The implausible illustration he offers for this is of a patient who undergoes surgery but who suffers less than an onlooker. In this same passage, we see a sharp contrast between Sextus and Hume:
Those who hypothesize that something is good or bad, or generally to be done or not done, are troubled in a variety of ways. In the presence of what they deem to be natural evils they think that they are persecuted; and when they are in possession of apparent goods, then because of their pride and their fear of losing them, they worry lest they may again fall among what they deem to be natural evils, and thus they experience no ordinary troubles. […]
Hence we deduce that, if what produces bad is bad and to be avoided, and if confidence that these things are by nature good and those bad produces troubles, then to hypothesize and be convinced that anything is bad or good in its nature is a bad thing and to be avoided. (PH III.237–8)
Notice that Sextus is solely concerned with the negatives here, namely, losing good things and gaining evil things. This is only one half of the dynamic of gaining and losing things. He omits that we are satisfied when we gain good things and that we feel relief when we skirt evil. If ill feelings are mitigated by sceptical detachment, then so are the positive emotions of good circumstances. In his examples, therefore, Sextus is presenting us with a narrow picture of the psychology of being affected by external circumstances.
Another part of the Outlines where we can see Sextus being selective is when he gives his overview of Pyrrhonism at the start of Book I. Sextus does not offer a concrete illustration of the advantage of living with radical epochê, but he briefly cites how both sceptics and non-sceptics ‘shiver and are thirsty and have other feelings of this kind’ (PH I.29). He insists that non-sceptics suffer extra due to their ‘believing that these circumstances are bad by nature’ (PH I.30). Here again we see Sextus only considering one half of the dynamic, ignoring how positive emotions are also mitigated by radical epochê.Footnote 34
So, Hume's sceptical crisis shows how we crave answers to basic questions about who we are, where we are, and which courses of actions to prefer to others (‘whose anger must I dread?’). Plausibly, a minimal degree of assurance on these things is necessary for basic psychological stability.Footnote 35 This affirms the picture of the ‘miserable existence’ of the Pyrrhonists that Hume provides at EHU 12.23. One might object that, given some examples, Sextus's view seems right. The response to this is to reaffirm the radicality of Pyrrhonian epochê. While a degree of detachment from undesirable occurrences can surely be beneficial, the Pyrrhonian takes a far more radical stance by unqualifiedly suspending judgement about all things: to do any more than passively acquiesce to appearances is to overstep the Pyrrhonian bounds. That the result of this should be tranquillity I take to be implausible.
5. Conclusion
Grasping the relationship between Hume's philosophy and ancient scepticism is a challenging task, but one that potentially reaps many benefits for our understanding of both history and philosophy. In this paper, I have offered a critical comparison of Hume's views on scepticism and the Pyrrhonism of Sextus Empiricus. I have argued that reading Hume's response to sceptical doubts allows us to see that the Pyrrhonist's claim that epochê leads to ataraxia is unconvincing. This comes across especially clearly in Hume's dramatic, first-personal struggle with scepticism in T 1.4.7. Hume does not merely state that radical epochê is impossible, but he shows that, even to the greatest extent that it is possible, it does not have pleasant psychological effects. Furthermore, Pyrrhonists saw philosophical investigations as one of their main targets of attack, but Hume desires to continue philosophising in the face of sceptical worries. So, although Hume finds sceptical arguments hard to refute and he incorporates some aspects of scepticism into his philosophy, his considered position is a far cry from Pyrrhonism.
Importantly, agreeing with Hume on the disconnect between epochê and ataraxia does not depend on being troubled by the particular sceptical doubts that Hume expresses in T 1.4.7, which are expressed in the language of Hume's idiosyncratic theory of mind. We only need to realise that the radicality of Pyrrhonism means that even those beliefs for which we crave assurance for psychological stability are impugned by the Pyrrhonist. Ultimately, what we gain from a comparison of Hume's scepticism and Pyrrhonism is a better understanding of different ways of reacting to the total suspension of belief that that radically sceptical arguments attempt to induce.Footnote 36
