2. The Formal Structure of Eudaimonism

The first step in elucidating eudaimonism as an ethical paradigm is to distinguish between form and content. Form is the collection of foundational features that all eudaimonists share that distinguishes them from other thinkers concerning happiness or ethics, such as subjectivists (morality or happiness is grounded purely in a subject’s beliefs or feelings), consequentialists (morality is impersonally grounded in results), deontologists (morality is grounded in duties or rules), and certain kinds of virtue ethicists (morality is grounded in character, but with no necessary appeal to happiness or personal well-being).Footnote ⁶ Content is those features that particular eudaimonists add to this general structure that distinguishes them from each other in their respective views on happiness. In this section, I will argue that, in form, all eudaimonists fundamentally conceive of happiness or flourishing (eudaimonia) as a good which is (a) partly objectively grounded in facts about human nature, (b) partly subjectively grounded in the beliefs and feelings of a subject, (c) structurally stable, and (d) exclusively intrinsically valuable. Through these four features, each eudaimonist offers their own rich account of what it means to live a truly happy (eudaimon) life.Footnote ⁷ In Sections 3–5, I will discuss the content-based differences between these thinkers in detail. In this section, however, I will largely restrict my focus to the formal commonalities between them.

Turning to my account of the formal features of eudaimonism, it is first important to note that eudaimonistic happiness is grounded in both objective and subjective considerations. Objectively speaking, eudaimonists partly ground happiness in (a) nurturing certain key third-personal features of human nature. We discover what features to nurture by more precisely attending to the nature of and relationship between the human soul and body. Socrates (Apology, 28b–38a; Euthydemus, 278e–282a),Footnote ⁸ Aristotle (NE, I.7–13, II.1–9, VI.1–8, 12–13, X.7–9), and the Stoics (DL, VII.85–102, 125–126; L&S, §§61, 63) argue that happiness is constituted by virtue as excellent states of the soul with respect to thought, feeling, and action.Footnote ⁹ Each considers “the best possible state of [the] soul” our ethical priority because things like bodily pleasure, bodily health, wealth, honour, and reputation are only good for us if our soul is healthy — that is to say, if we possess a virtuous character (Apology, 30b). For these eudaimonists, the central feature of the human soul, and that which is most indicative of its health or sickness, is reason. Virtue consists in the excellent realization of the soul’s rational faculty, meaning one reasons well (i.e., correctly), takes pleasure in being rational for its own sake, and acts based on their rational deliberations instead of mere passions. Key virtues, and thus constituents of happiness, are wisdom, courage, moderation, and justice as healthy states of the soul.

Epicurus and the Pyrrhonian Sceptics also ground happiness in the health of the human soul (Empiricus, Reference Empiricus2021, pp. 7–19, 27–33; LM, §§127–132; L&S, §§1, 71).Footnote ¹⁰ However, they think that happiness is constituted by tranquility in the soul. Both consider virtue qua reason important for happiness, but only insofar as employing reason effectively leads to a tranquil life. The Sceptics, admittedly, place doubt on the possibility of certain knowledge concerning reality, human nature, and value and promote suspension of judgement concerning all things. However, within the realm of what appears to be the case, they will nevertheless say that the Sceptic starts off as a person aiming for tranquility (Empiricus, Reference Empiricus2021, pp. 11, 27–29) and “whoever wants to be happy must [start by] consider[ing] […] how are things by nature (L&S, §1F2). The Sceptic, in other words, desires to be tranquil through understanding nature, but never succeeds in acquiring certain knowledge and instead achieves tranquility through suspending judgement. This point illustrates that the Sceptics end up with a weaker naturalistic foundation than do other eudaimonists (more on this point in the next section), but they still begin their ethical journey towards happiness with an examination of nature. Epicurus also distinguishes himself from other eudaimonists because he argues that eudaimonia is constituted by both the health of the soul and the health of the body in the form of joyful freedom from disturbance and freedom from pain, respectively (LM, §§128, 131). As we will see in Section 5, Epicurus is committed to this position because his atomism entails a relationship of strong interdependence between the soul and body.

In any case, despite differences in the particular details of their respective accounts of eudaimonia, each eudaimonist offers a naturalistic foundation for their conception of the happy life that lies in promoting (at least) the health of the human soul. In the next section, we will see that this naturalistic foundation for happiness differs in the robustness and precision of its content among eudaimonists, based on the extent to which they ground their ethical doctrines concerning goodness and happiness in non-ethical doctrines concerning the overall nature and relationship between reality, knowledge, and mind and body.

Subjectively speaking, because eudaimonists ground happiness in the health of the human soul, they are also (b) foundationally concerned with the first-personal features of beliefs and feelings. Happiness requires, whether instrumentally or constitutively (depending on the position in question), a virtuous character in terms of thinking, feeling, and acting correctly (i.e., in accordance with reason). It is not enough to merely perform a good (e.g., wise, courageous, moderate, or just) action. To be truly virtuous, and in turn happy, one must deliberately pursue wisdom, courage, moderation, and justice and take pleasure in being wise, courageous, moderate, and just (NE, II.3–6; LM, §132). Because virtue is integral to happiness, and a virtuous character involves pleasure, Socrates, Aristotle, Epicurus, the Stoics, and the Sceptics all understand happiness as a pleasant state of being in some sense. For Socrates, Aristotle, and the Stoics, pleasure is a necessary consequent of happiness as the life of virtue (Philebus, 20e–22b, 60c–67b; Republic, IX.581c–588a; NE, X.4.1174b15–1175a22; DL, VII.85–88), whereas for Epicurus and the Sceptics, happiness is itself constituted by a certain form of pleasure, namely tranquility.

In light of these details, eudaimonists deny that anyone could be blindly happy. If I am flourishing, then I will be aware of flourishing because I know what is truly good for me as a human being and I will be joyful in knowing that I possess this good. The beliefs/feelings of a subject therefore play a necessary role in grounding eudaimonistic happiness. However, because eudaimonia is also naturalistically grounded, beliefs/feelings do not play a sufficient role in grounding happiness. Simply believing and feeling that I am happy does not entail that I am indeed happy. Eudaimonists think that people can misunderstand their nature as human beings and precisely how things are beneficial (good) or harmful (bad) to their natural well-being. In other words, people can be mistaken about what truly constitutes human flourishing. Aristotle denies that popular goods like sensual pleasure, wealth, or honour per se constitute true happiness (NE, I.4–5). Epicurus argues that people often confuse objects of necessary vs. unnecessary desire, mistakenly placing their happiness in the latter instead of the former (LM, §§127–132). Finally, the Sceptics claim that ordinary people, and in fact other eudaimonists, are ultimately mistaken in thinking that they understand with certainty what is truly good or bad (L&S, §§1F, 71–72; Empiricus, Reference Empiricus2021, Chapter 6). The objective qua naturalistic and subjective qua affective consequently play individually necessary, but only jointly sufficient, roles in grounding eudaimonistic accounts of happiness.

These jointly naturalistic and affective considerations lead, in turn, to a concern with (c) the overall structural quality of one’s life. In pursuing happiness, eudaimonists are searching for a good which is “firm-footed and not in any way easily subject to change” (NE, I.10.1100b2–3). Eudaimonistic happiness, in other words, is meant to be stable and continuous, not momentary or intermittent. It is not the kind of thing which we can acquire in one moment, lose at another moment, and then regain. Eudaimonia is also not primarily about the length of one’s life (although, as we will see in the next section, Aristotle will give some weight to time in allowing one to flourish). Instead, eudaimonists foundationally see happiness as an overarching good the achievement and preservation of which we should structure our lives around (however short or long they may be). For Socrates, Aristotle, and the Stoics, this stable good is virtue as an excellent state of the soul which makes “the whole of [one’s] life harmonious” with their rational nature as a human being (DL, VII.89; see also Apology, 36b–d, 38a; NE, I.10.1100b4–1101a6). In contrast, Epicurus and the Sceptics envision this good in terms of stable tranquility free from chaotic feelings borne out of erroneous beliefs about the world and the value of things (DL, IX.45; LH, §§81–83; L&S, §§1A–F, 71A–C; Empiricus, Reference Empiricus2021, pp. 27–38). For both groups, it is better to spend one day living in a manner harmonious with one’s natural flourishing (namely, being virtuously rational or rationally tranquil) than to live 60 years with instability, self-destruction, or suffering. Structural stability is therefore a core feature of eudaimonia.

Finally, and most famously, eudaimonists consider happiness (d) the highest good. The highest good is:

• • “the end to which everything is the means, but is not itself the means to anything” (L&S, §21A1; see also Empiricus, Reference Empiricus2021, p. 27; L&S, §63A; NE, I.2); and

• • “self-sufficient” in that it “makes life desirable and lacking in nothing” (NE, I.7.1097b14–15; see also LM, §122).

Happiness as the highest good, in other words, is exclusively intrinsically valuable, the standard of value for all other things which are means to it, and inherently fulfilling.

As we have seen throughout this section, happiness is constituted by virtue for Socrates, Aristotle, and the Stoics and by tranquility for Epicurus and the Sceptics. Both groups consider the health of the soul a fulfilling good which is pursued only for its own sake and the ultimate reason for valuing anything else in life. However, they differ in what they take to be most indicative of this healthy state of being. The first group argues that the soul is truly healthy when one possesses a virtuous character. Pleasure, wealth, reputation, and various other things are only beneficial and good insofar as they are conducive to the achievement of or follow from wisdom, courage, moderation, and justice; in the absence of virtue, such things are often harmful and bad or at best morally neutral. The second group, in contrast, thinks that the ultimate health-oriented desire of the soul is tranquility. Being virtuous may be necessary to enjoy a stable state of tranquility, but we do not and should not value virtues merely for their own sake; instead, we do or should value wisdom, courage, moderation, and justice because they free the soul from all disturbance. In sum, what formally characterizes eudaimonists as moral philosophers is their commitment to a good which is (a) partly naturalistic, (b) partly affective, (c) structurally stable, and (d) exclusively intrinsically valuable.

It should be noted, however, that not all ancient moral philosophers are eudaimonists and that a moral thinker can be committed to some of these features but fail to be an eudaimonist. The Cyrenaics are an example of ancient moral thinkers who are not eudaimonists.Footnote ¹¹ Foundationally, they distinguish between eudaimonia as the totality of particular pleasures and the highest good as pleasurable sensations in the present (DL, II.86–93, X.136–137). While we can say that the Cyrenaics understand pleasurable sensation as a good which is (a) naturalistic and (b) affective, they nevertheless deny (c) and (d). First, the Cyrenaics deny that the highest good is (c) a stable condition because they ground it in fluctuating sensations in the present, with little concern for the overall structure of one’s life. Second, they deny that eudaimonia is (d) exclusively intrinsically good because it is valued for the sake of particular pleasures.Footnote ¹² Consequently, despite some commonalities with eudaimonists on the nature of the good life, the Cyrenaics place themselves outside of this ethical tradition by rejecting key features of eudaimonistic happiness.

In this section, I examined four foundational features that eudaimonists share, despite key differences in their respective accounts of happiness.Footnote ¹³ Traditionally, when scholars talk about eudaimonism outside of the context of antiquity, they tend to focus on the claim that happiness is the highest good, namely that happiness is (d) pursued for its own sake. There is sometimes mention of one or more of the other three features of (a) nature-based objectivism, (b) affective subjectivity, and (c) stability, but even then scholars rarely offer a systematic account of the intimate relationship between these formal features. My own analysis here, in contrast, offers a richer and more robust account of this ethical paradigm by clearly elucidating how these four features lead to a distinctive foundational conception of happiness as a good which is neither artificial, nor arbitrary, nor unreliable. Let us now turn, in the following sections, to the diverse contents that eudaimonists give to their formal conception of flourishing, which further illustrate the complex richness of this ethical tradition.

3. Weak Versus Strong Eudaimonism

One key formal feature of eudaimonistic happiness, as we have seen, is its (a) naturalistic foundation. Content-wise, however, eudaimonists differ in the extent to which they draw on nature in developing their respective ethical accounts of flourishing, some taking a basic and narrow approach and others a more systematic and all-encompassing one. Proponents of the basic approach I will refer to as “weak eudaimonists,” while those who adopt a systematic approach will be labelled “strong eudaimonists.” This is a distinction that scholars rarely acknowledge because of their tendency to focus on strong eudaimonists like Aristotle when outlining eudaimonism as an ethical theory.

Weak eudaimonists take a basic approach to this naturalistic foundation in the sense that they operate with basic truths, assumptions, or appearances about human beings in elucidating what a happy life consists of, but do not offer complete non-ethical theories about both reality and human nature. In other words, their ethical frameworks do not require an overall philosophical system of doctrines for elucidating the happy (eudaimon) life.

Socrates is committed as a philosopher to the discovery of truth and as an eudaimonist to ethical truths about how best to promote the health of the human soul (see footnote 8). Truths of this sort that he seems to endorse are (i) we always act based on what we believe is good (Protagoras, 358c–d), (ii) we all aim for happiness as the ultimate good (Euthydemus, 282a), (iii) it is essential for a happy life that we critically examine our beliefs, particularly our moral beliefs (Apology, 38a), (iv) the soul is in its best possible state, and thus happy, when we possess a virtuous character (Apology, 28b–30b; Euthydemus, 278e–282a), and (v) as true knowledge of good and evil, all the particular virtues are mutually inclusive (Laches, 198c–199e; Protagoras, 329b–333b). However, Socrates is also quite explicit about the limitations of his knowledge. First, he asserts that “I am very conscious that I am not wise at all […]. I do not know, neither do I think I know; so I am likely to be wiser than he [who does think himself wise]” (Apology, 21b–d). Socrates primarily places his wisdom in his clear recognition of his own ignorance of many things, which is why he considers (iii) critical examination of beliefs so important; we cannot be truly happy if we live believing that we understand things with greater clarity or certainty than we do. These five claims consequently do not represent things that Socrates takes himself to know with certainty. Instead, they represent claims he cautiously considers true because they have consistently stood up to critical examination, but that he is always sincerely willing to emend or abandon upon further reflection. Second, Socrates also largely restricts his inquiries to ethical matters, foregoing wider investigation into the nature of reality (Apology, 19b–d, 29a–30b; Phaedo, 96a–100a). He takes this course of action because of his general assertion of ignorance, but also because he thinks that we must first understand and cultivate the good of the soul in order to best approach metaphysical inquiries. In other words, only a person who is first (morally) wise can effectively engage in science and arrive at true understanding of reality.

Socratic happiness is naturalistically grounded insofar as it relies merely on basic considerations about the human soul. Socrates seems inclined towards understanding the soul and body as distinct to some extent because he argues that we should prioritize the health of the soul over the health of the body (Apology, 30a–b). However, he does not offer a complete, systematic explanation of the nature of the soul and body, let alone reality as a whole. Instead, he merely relies on certain metaphysical and ethical views about the soul and body that have consistently withstood critical examination to develop a coherent and compelling account of happiness, but of which he does not pretend to be certain. Socrates grounds happiness in key truths about human nature which elucidate what is and is not important for living a flourishing life. In this case, he offers a weak naturalistic foundation for eudaimonia because he does not think that understanding and achieving happiness requires fully developed non-ethical doctrines or an overall philosophical system concerning both reality and human nature.

The Pyrrhonian Sceptics also offer a version of weak eudaimonism. The Sceptics question their knowledge of things even more strongly than Socrates. In an attempt to discover natural and ethical truths for the sake of tranquility, the Sceptics start with how things appear to them and examine various positions on things, only to find “equal strength” among conflicting positions on nature and ethics (Empiricus, Reference Empiricus2021, pp. 27–29; see also L&S, §72). With respect to reality, for example, there are equally compelling reasons for endorsing hylomorphism as there are atomism (see below for further detail concerning these positions). Moreover, Pyrrho points out that there are even compelling reasons to think that reality is fundamentally “indifferent, unmeasurable and inarbitrable,” meaning nature does not admit of any positive account whatsoever (L&S, §1F3). With respect to ethics, equally compelling reasons can be given for the goodness and badness of things like knowledge, pleasure, honour, wealth, friendship, etc. The Sceptics offer, then, no theoretical doctrines as certain accounts of anything, because they have suspended judgement about the truth or falsity of doctrines. They instead operate practically based solely on appearances. Their naturalistic focus on the tranquility of the soul is derived from the mere observation that we seem to desire tranquility over everything else and that our pursuit of knowledge is also tied to this apparent end of tranquility (Empiricus, Reference Empiricus2021, p. 11). The Sceptics, however, do not present this claim as a doctrine that is built on evidence which clearly shows what is true and false. The Sceptics are Sceptics because it seems to them that every doctrine can be equally supported and refuted, so they rely merely on what appears to be the case. Pyrrhonian Sceptics therefore offer a weak eudaimonistic account because they are concerned with appealing to (human) nature in elucidating happiness, but their philosophical inquiries lead them away from offering certain doctrines or an overall philosophical system in favour of appearances, namely appearances pointing to the overarching importance of tranquility. However, the Sceptics, as people sincerely seeking truth and understanding, are only conditionally weak eudaimonists. They begin by trying to develop a philosophical system of doctrines that will bring them happiness (i.e., they begin with the intention of developing a strong eudaimonistic account and remain sincerely open to achieving such a thing), but in practice only find weak eudaimonism through tranquil suspension of judgement in the face of uncertainty.Footnote ¹⁴

In contrast, strong eudaimonists like Aristotle, Epicurus, and the Stoics offer accounts of eudaimonia that are deeply grounded in overall philosophical systems directed at explaining reality, knowledge, and human nature.Footnote ¹⁵ Through the foundation of his hylomorphism, which explains the universe in terms of substances as matter-form compounds (Physics, I–II; Metaphysics, Z–H), Aristotle divides the human soul (a form which realizes certain distinctive life capacities in matter) into the non-rational (bodily) faculties of nutrition, sensation, and appetite, and the rational (mental) faculties of calculation and understanding (NE, I.13.1102a26–1103a10, VI.1.1138b35–1139a18; On the Soul, II.3.414a29–415a12). In this framework, moral virtue represents the excellent realization of the appetitive/sensitive faculties, practical wisdom (phronesis) represents the excellence of the calculative faculty, and theoretical wisdom (sophia) represents the excellence of the understanding faculty. Aristotle then argues that there are two kinds of happiness: practical happiness and theoretical happiness (NE, I.13, II.5–6, VI.5–7, VI.12–13, X.7–8). Practical happiness is constituted by activities which follow from desiring goodness (moral virtue) and knowing how to achieve it in each situation (practical wisdom). Theoretical happiness is constituted by theoretical wisdom. This form of wisdom is constituted by true understanding of God, substance, matter, form, the celestial bodies, and various genera and species of substances (see, e.g., Categories, Metaphysics, On Generation and Corruption, On the Heavens, On the Soul, and Physics). Theoretical happiness represents the greatest excellence and flourishing of the human soul because it is the activity which most closely approximates the purely contemplative activity of God (NE, X.8.1178b7–33).

Epicurus asserts that the “goal” of understanding nature is happiness qua freedom from pain in the body and disturbance in the soul (LP, §85; see also LH, §83; LM, §§122, 128–129) and that the ultimate standard for truth/falsity and goodness/badness is “sense-perceptions and feelings,” namely, pleasure and pain (LH, §38; see also LM, §129).Footnote ¹⁶ We achieve bodily health through understanding the difference between objects of natural vs. non-natural and objects of necessary vs. unnecessary desire (and, in turn, pleasure), structuring our lives around only those things that are both natural and necessary (LM, §§130–131; PD, §§XXVI, XXIX–XXX).Footnote ¹⁷ We achieve tranquility of soul through understanding, among other things, (i) the atomistic and indeterministic nature of the universe, (ii) the perfection and blessedness of the gods, which precludes them from playing any direct, deliberate, or creative role in the universe, and (iii) the soul and body as perishable atomic compounds, which can only exist and function (i.e., feel and act) in conjunction with each other (LH, §38ff.; LM, §§123–127). Such knowledge frees us from worries about pleasing/displeasing the gods and the harms of death, because the gods have no interest in our actions, there is no cosmic plan with which we must live in accordance, and death (as the absence of existence and feeling) cannot in itself cause us any pain or disturbance.

The Stoics, conversely, ground happiness in their pantheistic, deterministic, and providential account of the universe and cognitive conception of emotions. First, they identify the universe with God as the active and rational principle which purposefully shapes matter into a necessary and perfect causal order (DL, VII.134–139; L&S, §§44C3–7, E3, 47). All things in the universe partake in God’s rationality to some degree, with humans manifesting this divine rationality to the greatest degree insofar as they are capable of deliberation and understanding. Virtue, and in turn happiness, consists of living in full agreement with one’s rational nature (DL, VII.87), which (partly) involves understanding that “nothing has happened which was not going to be, and likewise nothing is going to be of which nature does not contain causes working to bring that very thing about” through the deliberate and immanent influence of God (L&S, §55L2) and that humans exist “to contemplate and imitate [this providential, rational, and deterministic] world, being […] a tiny constituent of that which is perfect [rational and divine]” (L&S, §54H1). In other words, we are virtuous and happy insofar as we deliberately act through God and contribute to this rational order, understanding that all things happen necessarily as expressions of the rational and divine perfection of the universe. Second, the Stoics argue that emotions necessarily involve ethical judgements, passions (as diseases of the soul) reflecting erroneous value judgements and rational emotions (as healthy states of the soul) reflecting true judgements about the goodness, badness, and neutrality of things with respect to happiness (DL, VII.94–116). In light of their metaphysics, the Stoics argue that virtue qua reasoning well is the only true good, vice qua reasoning poorly is the only true bad, and everything else is morally neutral. Suffering and unhappiness are then the result of irrationality and misunderstanding of God, the universe, human nature, and the relationship between ourselves and other things.

These three eudaimonists, in contrast to Socrates and the Sceptics, offer accounts of eudaimonia which are grounded in fully developed philosophical systems which explicitly appeal to both ethical and non-ethical doctrines.Footnote ¹⁸ Furthermore, the happy person, in each eudaimonistic framework, also relies on some degree of understanding of how these ethical and non-ethical philosophical truths relate to each other for their flourishing.Footnote ¹⁹

In this section, we have seen that there is great diversity between eudaimonists concerning the relationship between knowledge of nature and happiness, something scholars do not always acknowledge when discussing eudaimonism as a general ethical theory. Weak eudaimonists, like Socrates and the Sceptics, rely merely on more or less basic non-ethical assumptions or facts about human nature in their respective conceptions of happiness. Conversely, strong eudaimonists, like Aristotle, Epicurus, and the Stoics, rely heavily on fully developed metaphysical, physical, epistemological, and psychological doctrines to determine what the happy life consists in.

4. Perfectionism Versus Non-Perfectionism

As we have seen, eudaimonia requires nurturing aspects of one’s nature as a human being in terms of things like health, virtue, reason, pleasure, or activity. But how strong or weak is this nurturing requirement? Does it require attending to all, most, or only some facets of human nature? Herein lies the distinction between perfectionism and non-perfectionism in the ethical context of eudaimonism. Perfectionist eudaimonists argue that happiness is constituted by substantially or fully realizing — “perfecting” — our (namely, rational) nature as human beings in the form of virtue.Footnote ²⁰ Non-perfectionist eudaimonists, in contrast, do not conceive of the relationship between human nature and happiness in terms of realization or perfection because they consider reason and other aspects of human nature to be non-essential, unnecessary, non-constitutive, or unknown. Because the most influential eudaimonists historically (namely, Socrates, Aristotle, and the Stoics) have been perfectionists, there is a tendency to equate perfectionism and eudaimonism, that is, to treat the realization of human nature as a feature of form within this ethical tradition. In this section, however, I argue that perfectionism and non-perfectionism are in fact features of content, because we find the presence and absence of both positions among eudaimonists in various ways.

The quintessential example of a perfectionist eudaimonist is Aristotle.Footnote ²¹ Aristotle argues that happiness is constituted by a complete life of virtuous rational activity in general (NE, I.7.1097b30–1098a21), and more particularly moral virtue and practical wisdom with respect to practical happiness and theoretical wisdom with respect to theoretical happiness (NE, I.13, II.1–6, VI.1, 5–7, 12–13, X.7–9). As we saw above, Aristotelian happiness is grounded in the virtues of the non-rational and rational faculties of the soul. The virtues are dispositions that realize these faculties in excellent ways. Moral virtue disposes the sensitive and appetitive faculties (i.e., one’s capacity to feel and act) towards following the guidance of practical wisdom as the excellent realization of the calculative faculty (i.e., one’s capacity to deliberate about how to act in each situation). Theoretical wisdom excellently realizes the understanding faculty. The virtues, in other words, properly direct and actualize our human capacities for moral feeling and action, practical reasoning, and scientific understanding.Footnote ²²

However, Aristotle argues that a happy life is more precisely an “active life” (NE, I.7.1098a7). Happiness is not constituted by the mere possession of virtuous dispositions. It is more rightly and substantially constituted by activities which successfully realize and express these dispositions: “it is not [merely] the finest and the strongest that are crowned [at the Olympic Games] but those who compete (for the winners come from among these), so too in life it is the doers that become achievers of fine and good things” (NE, I.8.1099a4–6, emphasis mine; see also I.5.1095b32–1096a, X.8.1178a29–1178b3). One does not become a gold-medal athlete simply by being athletic; Olympic victory is the result of successfully using one’s athletic abilities. Similarly, a truly happy life, as the excellent realization of human nature, lies in being morally and intellectually virtuous in both character and action. In other words, happiness requires successfully doing moderate, courageous, just, practically wise, and theoretically wise things that express healthy dispositions of the soul. Aristotle also argues that happiness requires more than “a single day, or a short time” (NE, I.7.1098a18–21). To be truly happy, one must live a life that is sufficiently long enough that they are able to (i) fully develop their human capacities from childhood to adulthood, and (ii) properly realize these capacities through virtuous dispositions and activities (NE, I.9–10, VII.13, X.7–9).Footnote ²³ Aristotelian happiness is therefore very much a matter of perfecting human nature by actively developing and expressing our moral and intellectual abilities as fully as possible.

I say “as fully as possible” because it is true that Aristotle allows for two kinds of happiness: practical happiness and theoretical happiness. It would seem that one could be happy through moral virtue and practical wisdom without theoretical wisdom or vice versa, insofar as the practical and theoretical virtues can be enjoyed independently (NE, VI.5–7, X.7–8). We might say then that Aristotle does not require the full realization of human nature for happiness.

There is some truth to this claim, however, with important qualifications. First, even for practical happiness, some theoretical wisdom is arguably required. To become morally virtuous and practically wise, one needs (through education) some scientific understanding of the faculties of the human soul and some understanding of how to nurture them in a healthy manner (see NE, I.7, I.13; On the Soul, II.2–7). Practical happiness still requires realizing both one’s practical and theoretical capabilities to some degree. Second, while practical happiness can be enjoyed independently of theoretical happiness, it is not clear that the converse is true. Remember that eudaimonistic happiness is (c) a stable state of being. To stably and unimpededly enjoy scientific understanding, one needs a healthy body and an environment supportive of their endeavours. This state of affairs is most reliably achieved through the prior possession of virtues like moderation, justice, and practical wisdom (NE, I.8, VI.12–13, X.8–9). Consequently, while theoretical wisdom can be enjoyed independently of the practical virtues, theoretical happiness requires the prior possession of practical happiness. Theoretical happiness is the greatest happiness not only because it represents the best kind of reason and virtue, but also because it entails the healthy realization of all of the human soul’s core faculties, bringing it as close as possible to divine perfection.Footnote ²⁴

While they also place happiness in virtue qua reason, Socrates and the Stoics offer a weaker, or more restricted, form of perfectionism.Footnote ²⁵ Like Aristotle, Socrates conceives of happiness as the perfection of human nature through virtuous dispositions and activities. More particularly, Socrates thinks that insofar as we clearly know what virtues like wisdom (Euthydemus), courage (Laches), moderation (Charmides), and justice (Republic, I) are (i.e., what specific domain of knowledge concerning good and bad each covers), we will necessarily act well, thereby realizing our rational and moral nature (Apology, 29d–30b; Euthydemus, 278e, 279c–282d; Laches, 198c–199e; Protagoras, 329b–333b). Because he sees the soul as wholly rational, Socrates does not allow for conflicts between knowing the good and doing the good as Aristotle does with his multifaceted conception of the soul in terms of rational and non-rational faculties. Furthermore, since Socrates does not pretend to any certain knowledge, a key part of virtue for him is constant critical reflection on the nature of the good, virtue, and how we ought to act in each situation (Apology, 38a). In other words, while Socrates offers a less definitive and robust account of things than does Aristotle, nevertheless both agree that happiness qua perfection of human nature requires being as rational and knowledgeable as possible.

Stoic perfectionism is constituted by the mere possession of virtue. Where Aristotle argues that happiness requires performing virtuous activities, the Stoics argue that living a happy life requires simply being virtuous in character. Because eudaimonia is (c) a stable state of being, the Stoics focus on what “is [fully] in our power” and what is “not [fully] in our power” (HB, §1.1).Footnote ²⁶ What is fully in our power is the health and virtue of the soul. The soul, as an instantiation of divine rationality (i.e., providence as an internal force), has no non-rational aspect (L&S, §§61B9, 65G, I4). Since the soul is wholly rational, its health depends entirely on how well or poorly one reasons and not on any external forces with respect to the body or one’s circumstances. When the soul reasons well, particularly about the value of things, it enjoys healthy and virtuous dispositions. However, while one has complete control over whether they are virtuous, they do not have complete control over whether they will be successful in performing virtuous actions. The success or failure of one’s actions is ultimately up to providence as an external force (L&S, §54). In some cases, God has deigned, in line with the overall rationality and goodness of the universe, that a virtuous person will be successful in their moral endeavours; in other cases, however, cosmic rationality requires the virtuous person to fail (HB, §§1–8, 15–19).

Being virtuous and happy is like an archer aiming at a target: one’s ultimate end “is to do all in one’s power to shoot straight” at the target, but “[t]o actually hit the target is, as we say, to be selected [i.e., preferred] but not sought” (OM, III.22).Footnote ²⁷ The archer’s true goal is to be a good archer, that is, to have the knowledge and skill to hit a bull’s-eye when no external factors interfere. If, however, an unexpected wind blows the arrow off-course or someone suddenly jumps in front of the target, the archer misses by no deficiency in their character or fault of their own, because such things are not truly within their control. Similarly, happiness is about being a virtuous person who has the knowledge and skill to do wise, courageous, moderate, and just things when circumstances permit — happiness does not require (as it does for Aristotle) always being successful in doing good things, since an individual good action may not fit into the overall providential order of the universe. It is because happiness is constituted merely by a virtuous character, and not virtuous activities, that the Stoic sage is said (again, contra Aristotle [NE, VII.13.1153b19–22]) to remain equally happy while being physically tortured on a rack, despite their pain and inability to perform virtuous activities (DL, VII.102–106). The Stoics are then perfectionists who conceive of eudaimonia in terms of properly realizing one’s rational nature, but because eudaimonia is supposed to be a structurally stable state, they limit this realization to what is fully in one’s control. Since they consider one’s character to be the only thing fully within one’s control, the perfection of human nature amounts merely to developing a virtuous character.

Epicurus and the Sceptics, in contrast, push against perfectionism of this sort in their respective accounts of happiness. Foundationally, Epicurus rejects a providential conception of the universe (LH, §§75–77; LM, §§123–124; PD, §1) and an essentialist conception of human beings (L&S, §§13E, I–J, 20J–L). Because the gods did not create the universe and their happiness qua tranquility leaves them uninterested in anything outside of themselves, there is no cosmic plan that human beings must structure their lives around, and deliberately realize, in order to be happy. Furthermore, because the universe is a random configuration of atoms, species have far less rigid and more contingent boundaries for Epicurus than they do for Aristotle and the Stoics.

While Epicurean happiness is naturalistically grounded in pleasure and pain, these are not features that are distinctly human, since various other things in nature are also sentient. When Epicurus argues that happiness is constituted by pleasure, he specifically means the katastematic (i.e., stable or restful) pleasures of “lack of pain in the body and disturbance in the soul” (LM, §131) or “peace of mind and freedom from pain” (DL, X.136). The happy life, in other words, consists simply of enjoying unimpeded bodily and mental functioning. Everything else, including virtue, has instrumental value because it is pursued for the sake of katastematic pleasure (DL, X.138; LM, §§128, 132; OM, I.42). Wise, courageous, moderate, and just dispositions and activities are mere tools for achieving and maintaining freedom from suffering. With respect to reason, Epicurus argues that practical wisdom is more important than scientific understanding, because scientific understanding matters only to the extent that it helps us remove pain and disturbance. In fact, Epicurus asserts that if ignorance of nature did not often cause pain, anxiety, and fear, “then we would have no need of natural science” (PD, §XI). Activities and knowledge that do not directly produce freedom from suffering are, in turn, considered objects of unnecessary desire. They neither constitute nor increase happiness; the enjoyment of them merely diversifies one’s prior state of eudaimonia qua healthy being (PD, §§III–IV, XVIII, XXIXn20).

Taken together, these points indicate that Epicurean happiness is not constituted by the perfection of human nature in any significant sense. Epicurus has no strict and strong conception of what human nature is and how it should develop beyond avoiding impediments to bodily functioning (pain) and mental functioning (disturbance). Admittedly, one might say that the Epicurean seeks to actualize the capacity of the soul and body for stable functioning. On these grounds, Epicureanism would be a version of weak perfectionism. However, this simplistic end of katastematic pleasure is a far cry from what Socrates, Aristotle, and the Stoics have in mind with their robust project of moral and intellectual perfection. While virtues like practical wisdom, courage, moderation, justice, and scientific understanding play a necessary instrumental role in living well for Epicurus, they do not have intrinsic value. Perfectionists like Aristotle and the Stoics value moral conduct and scientific understanding for their own sake as excellent expressions of human nature, leading them to cultivate these things as fully as possible (barring the limitations of circumstance) — they aim, in other words, to be as moral and knowledgeable as possible. These thinkers argue that one can only truly be happy by sincerely doing all they can as a moral and rational human being.

Epicureans will also aim to be moral and to understand nature to promote their happiness, but because their happiness resides in mere freedom from suffering, they are not required to do all that they can morally or scientifically. For example, Epicureans engage in politics only to the extent that it is required for the security and tranquility of themselves and their fellow citizens; they feel no moral duty to attempt to do all they can to improve their society or state (L&S, §22; PD, §§XIV, XVII, XXXI–XL). Similarly, Epicureans can be content with understanding multiple potential explanations for a certain meteorological phenomenon (e.g., tornadoes), without pinpointing which one is the actual explanation, because they only need to know enough about meteorological phenomena to be free of fear and anxiety (LP, §§85–87). Of course, happy Epicureans may decide to enter politics or engage in scientific inquiry beyond what their tranquility requires, but in such a scenario, they understand their actions as a matter of preference (i.e., an object of unnecessary desire) whose success or failure can only vary their experience of happiness qua tranquility and not enhance or undermine it. Consequently, Epicurus is arguably not a perfectionist because his account of happiness requires only the basic joys of bodily and mental functioning. The realization of much of our moral and scientific capabilities is considered unnecessary and merely instrumental or preferential within his eudaimonistic framework.

The Sceptics offer a foundation that is even more clearly non-perfectionist than Epicurus, due to their commitment to a non-dogmatic position. Because the Sceptics have evaluated various positions on reality and human nature (including those of Socrates, Aristotle, the Stoics, and Epicurus) and found equal reasons to affirm and deny these positions, they suspend all certain judgement concerning such matters. The Sceptics, in other words, offer no certain knowledge or true doctrines about anything, let alone human nature (Empiricus, Reference Empiricus2021, pp. 13–20). In fact, for some Sceptics, most notably Pyrrho, it is not even clear that reality is in itself intelligible, structured, or ordered to begin with; reality may simply be “indifferent, immeasurable and inarbitrable” (L&S, §1F3). A perfectionist conception of eudaimonistic happiness requires a definitive account of human nature which specifies key features to be cultivated and what it means to properly realize such features relative to human well-being. Furthermore, if human nature is understood to be essentially rational, perfecting it requires cultivating some knowledge of things. The Sceptics, however, have no definitive account of human nature, and thus no conception of human perfection, with which to work. Reason certainly plays an important role in the Sceptics’ activities, but only to the extent that rational reflection reveals their overarching desire for tranquility, their lack of certain knowledge about things, and their experience of tranquility when they suspend judgement in the face of this uncertainty. As sincere reasoners, the Sceptics are always open to being persuaded that a certain eudaimonistic position is correct, including a perfectionist one. However, insofar as no perfectionist position presents itself to them as more persuasive than others, they remain Sceptics and not dogmatists or perfectionists. Sceptic happiness consequently involves no notion of perfecting human nature because it consists of mere tranquil suspension of judgement concerning all theoretical matters.

In this section, we discussed different versions of perfectionism and non-perfectionism among eudaimonists. Aristotle argues that human nature is perfected through the realization of virtuous (namely, rational) dispositions and activities concerning morality and scientific understanding. Socrates conceives of human perfection in terms of both knowing and doing good, which requires constant critical reflection on the nature of goodness. Here scientific understanding plays a more restricted role due to Socrates’s cautious approach to wisdom. The Stoics also offer a restricted form of perfectionism in terms of the possession of mere virtuous dispositions, due to their joint commitments to a providentialist metaphysics and the stability of eudaimonia. Epicurus, in contrast, pushes against a traditional perfectionist mindset in light of his non-providentialism, non-essentialism, and qualified hedonism, which leads him to restrict happiness to the realm of joyful freedom from suffering and in turn to consider the expression of much of our human capacities unnecessary for being eudaimon. The Pyrrhonian Sceptics also reject a perfectionist account of happiness by virtue of their non-dogmatic commitment to tranquilly suspending judgement about doctrines concerning reality and human nature. Consequently, Epicurus and the Sceptics illustrate that, contrary to traditional scholarly discussion of eudaimonism, not all eudaimonists are perfectionists.Footnote ²⁸

5. Intellectualism and Materialism

The final key debate among eudaimonists that we will discuss here concerns what role the mind and the body play in happiness. Do corporeal things like bodily health, pleasure, and activity or intellectual things like mental health, scientific understanding, and tranquility (i) constitute happiness, (ii) function as necessary means to happiness, or (iii) play no necessary or direct role in happiness? An intellectualist will consider mental goods superior to bodily goods, attributing a constitutive role to the mind in happiness. A materialist, conversely, will argue that bodily goods are superior to mental goods, conceiving of happiness in terms of bodily well-being.Footnote ²⁹ As we will see, Socrates, Aristotle, the Stoics, and Epicurus all endorse some form of intellectualism, which considers the goods of the mind to be more valuable than those of the body, based on their respective ontological frameworks.

The exception here is the Sceptics. It is true that the Sceptics think of happiness in terms of tranquility as a “trouble-free condition, or calmness, of the soul,” which may suggest that they are intellectualists to some extent (Empiricus, Reference Empiricus2021, p. 11). However, because they are non-dogmatists, the Sceptics do not commit themselves to any definitive conception of the relationship between mind and body. From their standpoint, various positions are equally compelling and problematic upon reflection, thereby requiring suspension of judgement. As a result, the Sceptics will never definitively pursue, reject, or disregard things like scientific inquiry, bodily activity, or sensual pleasures. They will instead simply respond to such things in whatever manner appears best at that moment (in particular, according to the customs and laws of the society in which they currently live), with no true commitment to the general equality/inequality or goodness/badness/neutrality of mental and bodily things (Empiricus, Reference Empiricus2021, pp. 19–33). In other words, the Sceptics are, at best, intellectualists in the weakest and least committal sense possible insofar as they pursue tranquility for its own sake, but always leave open the possibility that other things are equally worth pursuing upon further critical reflection. Non-dogmatic eudaimonism therefore leads away from intellectualism or materialism.

Returning to dogmatic eudaimonism, however, most ancient thinkers assign a central place to the health of the mind in promoting a happy life, relative to the weakness or strength of their respective naturalistic foundations. Socrates asserts that one should not “care for [one’s] body or [one’s] wealth in preference to or as strongly as for the best possible state of the soul” because “excellence [i.e., a virtuous character] makes wealth and everything else [including the body] good for men, both individually and collectively” (Apology, 30b). In particular, it is the virtue of wisdom which is most central to living a happy life. Socrates argues that things like bodily health, food, sensual pleasure, beauty, wealth, and political power are not in themselves “good by nature” since such things can be harmful when one is ignorant of how to use them well (Euthydemus, 281d). It is only when the soul possesses wisdom in the form of moral knowledge, and subsequently acts through the guidance of that knowledge, that bodily and external things are rendered good and harmonious with living well. How this is so becomes clearer through Socrates’s commitment to the virtues of wisdom, courage, moderation, and justice as mutually inclusive (if not identical) expressions of knowledge of good and evil (Protagoras, 329b–d, 358–361c). In this case, being wise entails being courageous, moderate, and just, and vice versa. A wise person never acts excessively, allowing them to use and enjoy health, food, pleasure, beauty, money, and power in sustainable and harmonious ways. They know what risks are and are not worth taking for such things. Finally, they know how to interact with others in healthy and fair ways that ensure both parties are not harmed by each other in their pursuit of these goods. Although Socrates places less importance on scientific knowledge of non-ethical truths due to his weak eudaimonism, it is nevertheless the case that reason and understanding are the highest goods in his ethical framework. The goods of the soul or mind — namely, the virtues as expressions of moral knowledge — are both intrinsically valuable and constitutive of happiness, while the goods of the body are merely instrumentally valuable and derive their goodness from the health and virtue of the soul. It is this reason-oriented hierarchy that ultimately makes Socratic eudaimonism intellectualist, albeit with a predominantly moral focus.Footnote ³⁰

Aristotle, the Stoics, and Epicurus, as strong eudaimonists, offer far more robust and nuanced accounts of the intellectual nature of happiness which are grounded in rich doctrines concerning God, the universe, and mind and body.Footnote ³¹ In the metaphysical realm, Aristotle explains the existence of the universe by appeal to the complex relationship between God, form, and matter. God, as the highest kind of being and ultimate cause of the universe, is essentially eternal, immaterial, intellectual, and active. The Aristotelian God, as a being of self-reflexive thinking of thinking, non-purposefully and indirectly shapes the universe insofar as matter approximates God’s eternal and rational nature to varying degrees (Metaphysics, Λ.6–10).

Matter is purely passive and indeterminate being, lacking any positive features of its own. Matter only gains features and structure to constitute the universe through the (non-purposeful) influence of God and forms (Physics, I.7; Metaphysics, Z–H; On the Soul, II.1). It thus functions as a passive principle, that which is acted on. Forms, conversely, function as the active principle, that which gives determinate being to matter. Forms are in themselves immaterial, shaping matter into something determinate from within and have no independent existence outside of matter. An individual is then a combination of matter (i.e., that which is acted on as a subject of potential features) and form (i.e., that which actualizes certain features in matter). Ultimately, Aristotle considers immaterial and intellectual being ontologically superior to material, non-thinking being because the former is associated with divinity and activity, while the latter is associated with passivity and is dependent on the former for any sort of determinate existence.

This same sort of hierarchy in favour of the immaterial/intellectual also applies to the relationship between the soul and body. For Aristotle, in the case of human beings, the soul is a special kind of form which realizes certain life functions in matter (namely, nutrition, sensation, appetite, calculation, and understanding) to form a human body (On the Soul, II.1–2; NE, I.7, VI.5–8). While the soul qua form as a whole cannot exist outside the body, Aristotle suggests that the rational part of the soul can (in some sense) enjoy immortal existence apart from the body (Metaphysics, Λ.3.1070a22–25; On the Soul, II.1.413a6–7, III.4–5). In the ethical realm, Aristotle argues that happiness consists in “the function of human beings,” or that activity which is most characteristic of human nature (NE, I.7.1097b25–26). While humans possess bodily faculties like nutrition, sensation, and appetite, it is reason that Aristotle thinks most defines human nature and distinguishes it from other living things. In particular, he adamantly rejects the notion that happiness is constituted by bodily pleasure. Aristotle considers a life structured around such pleasures “utterly slavish” because it is best suited to “grazing cattle” and not human beings with the abilities to deliberate about how best to live and to understand the world around them (NE, I.5.1095b20–21). As a result, he places happiness in virtuous rational activities, namely practical wisdom and theoretical wisdom.

Bodily goods serve an instrumental and subservient role. On the one hand, because humans are partly corporeal in nature, bodily health and “the availability of nourishment” are necessary for the rational part of the soul (i.e., the mind) to function well (NE, X.8.1178b35). If my body is ill, that is, if my nutritive faculty is impeded in its functioning, then my rational faculty will be hindered in thinking clearly and effectively. The health of the body is thus a necessary means to facilitating the health of the mind. On the other hand, I can only maintain a healthy body and use my sensitive and appetitive faculties in healthy ways through the guidance of practical wisdom. While I can train myself to desire and take pleasure in courageous, moderate, and just actions, I cannot know how to realize such actions in each situation without excellent deliberation (NE, VI.12–13). With respect to moderation, what and how much I should eat for the sake of adequately nourishing my body will depend on various factors, such as whether I am currently healthy or ill (e.g., steak and wine vs. soup and tea), what kinds of food are available to me (e.g., steak, wine, lobster, carrots, apples, rice, water), how much food is available to me (i.e., a large or small amount), and what kinds of activities I engage in (e.g., reading, writing, jogging, wrestling, basketball, testing out scientific hypotheses). My sensitive and appetitive faculties, in other words, are only in a healthy and morally virtuous state when they are “obedient to reason,” namely, practical wisdom (NE, I.13.1102b27).

However, Aristotle considers practical wisdom (the excellence of the calculative faculty) and theoretical wisdom (the excellence of the understanding faculty) distinct faculties of reason, and the latter superior to the former (NE, VI.5–9, X.7–8). Practical wisdom pertains to mutable truths concerning the contingencies of day-to-day life and relies on a variety of external goods relative to specific moral virtues to be exercised (e.g., objects of sensual pleasure for moderation and interactions with other people for justice). Theoretical wisdom, in contrast, pertains to immutable and eternal truths concerning God, the universe, and essences qua forms, relies on fewer external goods than moral virtue/practical wisdom to be enjoyed, and most closely approximates the non-purposeful contemplative activity of God. The inferiority of practical wisdom lies in its close connection to the bodily faculties of the soul and changeable material conditions, while the superiority of theoretical wisdom lies in its close relationship to immaterial, divine, and neverending being and its comparative distance from all that is bodily and perishable.

Furthermore, practical wisdom (and happiness) is partly instrumentally valuable because of its role in bringing theoretical wisdom (and happiness) “into existence” (NE, VI.13.1145a9). Moral activities like courage, moderation, and justice are intrinsically valuable as expressions of the practical dimension of human reason and wisdom, but they also serve as a means to creating a healthy and secure environment for scientific inquiry into and understanding of eternal truths. Theoretical wisdom, in contrast, is exclusively intrinsically valuable, because all other non-rational and rational faculties are subservient to the understanding faculty but it is not subservient to any of them. Thus, for Aristotle, the theoretical (and least material) dimension of reason is most representative of human happiness as (d) the highest good.

In the Stoics, we find a substantially different account of the relationship between the intellectual and corporeal. Ontologically, the Stoics combine materialism and pantheism. They consider reality fundamentally extended in length, breadth, and depth because anything non-extended or incorporeal is incapable of “acting or of being acted upon,” and thus does not really exist (L&S, §45A; see also §§B–C, 27B). More precisely, reality consists of void, matter, and God. Void is infinite empty space which contains the finite universe within it. The universe itself is constituted by two eternal and interconnected corporeal principles, with matter as the passive principle and God (theos) or reason (logos) as the active principle. Matter, as a featureless body, is shaped into the structure and order of the universe from within by God as an intelligent, purposeful breath or fire. God, in other words, functions as the soul of the universe and matter its body. In fact, because God is inseparable from matter, and the universe as a determinate being only exists through the immanent influence of God qua soul, there is a substantive sense in which the universe just is God as a living thing possessing perfect rationality (DL, VII.134–139, 147; L&S, §§44C–E, 46E–F, 47C). Everything in the universe, in turn, participates in God’s soul and rationality to some degree. Humans share in God’s rationality to the greatest degree insofar as they possess not only a rationally determinate structure, but also the capacity for reason itself. Furthermore, because the human soul is part of God’s soul, it has no non-rational faculty, but is instead purely rational in nature (DL, VII.110, 139; L&S, §§45C–D, 47, 53). The Stoics consequently consider divinity, activity, and rationality inherently corporeal, the non-extended and incorporeal being not merely passive, but altogether non-existent.

Despite this materialistic foundation, however, in the ethical realm, the Stoics consider mental things to be superior to bodily ones. First and foremost, happiness is about living according to nature, in particular what is distinctive to human nature and fully within one’s control. From this foundation, the Stoics distinguish between what is good, bad, wholly morally indifferent, indifferent but preferred, and indifferent but dispreferred. Good and bad represent what directly promotes or undermines, respectively, happiness as the perfection of one’s nature. Only things that are fully within one’s control can be good or bad. Something is morally indifferent, conversely, if it does not directly “contribute either to happiness or misery” (DL, VII.104) and is not fully within one’s control (HB, §1). Wholly indifferent things (e.g., the number of hairs on my head or the length of my nails) have nothing whatsoever to do with perfecting my nature. Preferred and dispreferred indifferents are indirectly related to happiness in the sense that it is natural for human beings (within their limited power) to pursue the former and avoid the latter, even if success in these endeavours has no effect on one’s happiness.

Since humans are inherently intellectual creatures through their strong participation in divine rationality, and subsequently have complete control over their use of reason, the “peculiar good” of human nature which constitutes the health of the soul and happiness is “perfect reason” (L&S, §63D). In this case, perfected reason involves theoretical understanding of the materialistic, pantheistic, and deterministic nature of the universe and practical understanding of the true value of things within the universe (L&S, §§61D1–2; see also §§61B–H; DL, VII.125–126). The only true good with respect to happiness, then, is a healthy soul which reasons well (i.e., virtuously) and enjoys tranquil emotions, while the only true bad is an unhealthy soul which reasons poorly (i.e., viciously) and suffers turbulent passions.

Because the states of the body are partly within our control and partly up to providence, they are morally indifferent (DL, VII.102–103). I can be equally happy whether my body is healthy or sick, or experiencing pleasure or pain, so long as I am rational and virtuous (namely, wise, courageous, moderate, and just) in character. The Stoics find that a common source of unhappiness lies in passionate obsession with the body, namely erroneously pursuing sensual pleasures as if they were good and the true source of happiness and avoiding sensual pains as if they were bad and the true source of unhappiness (HB, §34). With that said, the Stoics grant that bodily health and pleasure are preferred indifferents and bodily sickness and pain are dispreferred indifferents. It is natural, as dictated by the providential order, that human beings should pursue health and pleasure and avoid sickness and pain, so a virtuous and eudaimon person acts in line with these natural inclinations to the best of their ability (DL, VII.105–110; OM, III.20–22, 51–61). However, in their wisdom, the virtuous person also understands that their happiness requires only that they rationally aim to care for the body. Because it is ultimately up to God what happens to the body, any failure on the virtuous person’s part to achieve their goals in this respect is not their fault and thus not an impediment to the excellent quality of their life.

In sum, the mental and bodily have a complex relationship for the Stoics. On the one hand, everything, including God, the soul, and reason, is ontologically corporeal in nature. On the other hand, there is a central ethical inequality between mind and body. Since the Stoics place what is good/bad in what is fully in our control and what is morally neutral in what is not fully in our control, mental things and bodily things have drastically different moral values. Only mental things can be good or bad, because only reason is fully within our power as human beings. Bodily things, because they are partly subject to external forces, are neither good nor bad per se. They are at best preferred or dispreferred relative to human nature, but with no direct impact on happiness or unhappiness. Stoic eudaimonia is thus strongly intellectualist in the sense that only the health of the mind is truly good.

Epicurus offers a similarly nuanced account of materialism and intellectualism in his own philosophical framework. Like the Stoics, Epicurus grounds reality in corporeal being because anything incorporeal “can neither be nor be acted upon” (LH, §67). In this case, however, reality is constituted by void and atoms. Atoms are imperceptible, indivisible, and eternal bodies of various kinds which indeterministically move through empty space and collide to form compounds, such as the gods, worlds, celestial bodies, and natural things like rocks, dogs, and humans (LH, §§40–45, 54, 61–65; LP, §88ff.; L&S, §11B).

Of particular note here is Epicurus’s materialistic conception of the gods and humans. The Epicurean gods are “indestructible and blessed” atomic compounds (LM, §123; see also PD, §1). In light of their atomic nature and perfectly tranquil and eternal state of being, Epicurus argues that the gods play no direct role in creating or structuring reality. Contra the providential and deterministic cosmological picture of the Stoics, atomic compounds are simply formed by random collisions between atoms. There is no purposeful design to reality on the part of the gods. They instead live blissfully in the void — namely, in the space between worlds (intermundia) — separate from and wholly unconcerned with the creation, destruction, and various affairs of worlds and individuals (LH, §§38–39, 76–77; L&S, §§13D–I, 23A).

Humans, in contrast, are mortal and constituted by soul and body as distinct, but closely connected, atomic compounds. The soul is specifically “a body [made up of] fine parts” which are mixed together and spread throughout the denser atomic compound that is the human body (LH, §63). Humans are mortal because their soul and body mutually rely on each other for their existence and powers. First, the constituent atoms of the soul cannot maintain their fixed relationship to each other outside of their infusion with the body, nor can the body qua living thing maintain the constitutive relationship between its atoms without the soul. Second, the soul is only capable of sense-perception, feeling, thought, and action through the medium of the body, while the body has no such life functions without containing a soul within it (LH, §§63–65). Human beings can also enjoy blessedness; however, their blessedness is not permanent or indestructible, like that of the gods. The states of human beings are mutable and human blessedness is something that must be maintained through constant nourishment and reflection. Consequently, although they offer drastically different accounts of reality (one atomistic and indeterministic, the other deterministic and providential), in substance Epicurus shares with the Stoics (contra Aristotle) a foundational ontological commitment to the essential connection between corporeality, divinity, activity, and rationality.

In the ethical realm, Epicurus’s hedonism offers a noteworthy and nuanced contrast to the intellectualism of Socrates, Aristotle, and the Stoics. Similar to Aristotle, Epicurus thinks that mental goods are in some sense dependent on bodily goods, and thus the body plays a necessary and direct role in promoting happiness. In this case, he argues that the “[p]leasures and pains of the mind […] originate in bodily pleasures and pains” (OM, I.55). First, as an atomist, the soul and body, while different, are nevertheless fundamentally corporeal for Epicurus, so there could be no mental pleasures that are not bodily in nature. Second, because the soul and body exist and function co-dependently, the health (i.e., necessary kinetic and katastematic pleasures) of the soul strongly depends on the health (and pleasures) of the body. Furthermore, this materialist conception of soul and body leads Epicurus to say that bodily pleasures are not only necessary for happiness, but also constitutive of this ultimate state of being. Recall that Epicurean happiness consists of both bodily and mental katastematic pleasure in the form of “lack of pain in the body and disturbance in the soul” — that is to say, homeostasis and peace of mind (LM, §131). Where eudaimonists like Socrates, Aristotle, and the Stoics consider happiness predominantly (if not solely) mental in nature, Epicurus places the eudaimon life in both the mental and bodily realms.

In light of its atomistic foundation and the subsequent constitutive role of body and mind, prima facie it would seem that Epicurean happiness is not intellectualist. However, although Epicurus attributes a greater role in happiness to the body than do his fellow eudaimonists, nevertheless like them he considers mental goods to be superior to bodily ones. In this case, mental pleasures are superior to bodily pleasures. According to Epicurus, whereas bodily pleasures are experienced with respect to the present (i.e., the here and now), mental pleasures can refer to the past, present, and future, through recollection, reflection, and anticipation, respectively. Each of these three kinds of mental pleasure are invaluable in combatting bodily pain and mental disturbance (DL, X.137; OM, I.55–56). Recollection allows one to enjoy memories of the past which overwhelm or distract from pain experienced in the present. Epicurus, while suffering severe pain from gastro-intestinal issues on his deathbed, famously describes himself as experiencing “joy in [his] soul produced by the recollection of discussions” with friends (LI).Footnote ³² Reflection similarly allows us to take pleasure in present goods, such as nutrition, taste, homeostasis, peace of mind, scientific understanding, literature, and loved ones. Finally, pleasures borne out of anticipation can be quite potent with respect to one’s overall state of being. When facing pain, we can content ourselves with the knowledge that severe pain always comes to an end in terms of recovery or death and chronic pain can always be overwhelmed by other reflective and recollective pleasures in the future. Friendship is also a powerful good, because it grants a sense of tranquil security that we always have the intimate concern and support of others in living well (OM, I.49, 57, 66–70; PD, §IV).

While both mental and bodily pleasures (at least initially) constitute happiness, the mind has greater resources than the body for maintaining happiness over time due to the former’s greater modal scope. Furthermore, the example of Epicurus on his deathbed indicates that one can remain eudaimon in the face of bodily pain, so long as they enjoy stable peace of mind grounded in recollective, reflective, or anticipatory pleasures. This point about the mind also explains why the Epicurean sage being tortured on the rack is said to be happy, despite their bodily suffering (DL, X.118). Epicurus does not think that freedom from bodily pain alone is sufficient for happiness, either initially or in the long run, if one’s mind is distressed. The body, in other words, plays a central constitutive role in happiness, but has less impact in maintaining happiness than does the mind. However, because of the dependence of mental pleasures on bodily pleasures, it may be that the mind cannot strictly speaking function or experience freedom from mental disturbance without the body enjoying some degree of unimpeded natural functioning qua freedom from bodily pain (Rist, Reference Rist1972, pp. 110–111, 171–172). Gastro-intestinal issues and bodily torture, after all, do not impede and pain every part of the body, only certain parts. In this case, while mental pleasures are more useful than bodily pleasures, mental katastematic pleasure alone or bodily katastematic pleasure alone is not sufficient for eudaimonia — one is only truly happy insofar as they experience both kinds of pleasure to some degree.Footnote ³³

In this section, we have seen that, while ethical intellectualism is a dominant trend in ancient eudaimonism, nevertheless not every ancient thinker within this tradition is clearly or equally an intellectualist. On the one hand, Socrates and Aristotle straightforwardly embrace an intellectualism which prioritizes mental goods over bodily ones and encourages the acquisition of as much understanding as possible (notwithstanding differences in the scope of knowledge each thinks that they can offer). On the other hand, the Sceptics are not dogmatically intellectualists or materialists. They merely point to the apparent value of tranquility, with no fixed views on the overall ontological and ethical relationship between mind and body and their respective goods. In fact, it is a crucial dimension of the Sceptic approach to eudaimonia that one consistently suspends judgement towards such things (barring significant and clear evidence of one position over all others). The Stoics endorse both materialism and intellectualism. Ontologically, they understand everything, including God, the universe, and the soul, to be corporeal in nature. However, ethically, they restrict goodness and happiness solely to the realm of the mind, all other corporeal things being morally indifferent. Finally, despite his commitment to the superiority of mental pleasure, Epicurus arguably offers the weakest form of intellectualism by virtue of his atomism and hedonism. On his account, mind and body are co-dependent atomic compounds that can neither exist nor function independently of each other, which leads Epicurus to consider the enjoyment of mental and bodily health to be equally constitutive of happiness. Furthermore, because pleasure is the highest good, Epicurus argues that scientific understanding is merely instrumentally valuable to the extent that it promotes peace of mind — beyond this threshold, the acquisition of knowledge is unnecessary and at best preferential. Consequently, with the substantive differences between these thinkers in mind, it is clear that eudaimonism allows conceptual space for a great diversity of accounts concerning the roles of mind and body in living a happy life. Contrary to traditional scholarly focus on Aristotelianism, eudaimonism is not restricted to dogmatism or intellectualism concerning the mental and bodily dimensions of human existence.