2.1 Plato and Aristotle

Plato and Aristotle, both ontologically and ethically, consider immaterial qua non-extended being superior to material being, by virtue of their views on God, matter, and form. God is understood to be essentially and eternally self-subsisting, immaterial, intellectual, and active in nature as the ultimate cause of the structure of the material universe, and those beings within it (Timaeus 28aff.; Metaphysics Λ).Footnote ⁵ For Plato, God plays a direct causal role as a purposeful designer who structures the universe with respect to a pre-existing model (i.e., Form) of the Good. Conversely, for Aristotle, God plays an indirect and non-purposeful causal role through final causation as an object of desire, in the sense that all other beings (intentionally or non-intentionally) strive to approximate the contemplative and eternal perfection of God.

Pure (prime) matter, while not created by the Platonic or Aristotelian God, is essentially passive as that which is acted on, but cannot in itself act on anything else (Timaeus 49a–50e; Physics I.8.192a31; Metaphysics घ.3.1029a7–26; H.1.1042a27–28; Λ.2–3). The universe is created through the (purposeful or non-purposeful) influence of God, which imposes a determinate structure on matter as the substratum or basic stuff out of which various kinds of beings are brought into existence. Matter, in other words, can be understood as the passive principle in the constitution of the universe and individual things (i.e., natural substances or self-subsisting beings). The active principle, that which (indirectly or directly) acts on matter to give it determinate being, is form. For Plato, Forms are self-subsisting, immaterial, eternal, and perfect ideas (e.g., the Form of Good, the Form of Beauty, the Form of Man, the Form of Table, etc.) which exist outside of matter (Republic V–VII; Symposium 204a–205a, 210e–211e).Footnote ⁶ They influence matter indirectly in the sense that material things (in some way) participate in or imitate these perfect ideas, like a photograph or shadow that only superficially captures the nature of an object (Republic 514a–517a). For example, all material things that can truly be described as beautiful obtain their beauty from the Form of Beauty, insofar as their constituent matter superficially imitates this Form (Phaedo 100c). Matter (as passive being) cannot, in itself, bring into existence or constitute goodness, beauty, men, tables, or any other determinate kinds of being. It requires the active influence of God (intentionally) and Forms (non-intentionally) as immaterial beings. For Aristotle, forms are also immaterial and give determinate being to matter in various ways. However, contra Plato, he argues that forms do not and cannot exist outside of matter. They instead play a direct causal role in the existence of the universe and individual things, giving matter determinate being from within as essences. In other words, individual things are a combination of matter and form, matter being necessary as the recipient of an essence and form being necessary as this essence realized in matter (Physics I.7; Metaphysics Η; घ).Footnote ⁷ At this juncture, we can see that, despite some differences in the finer details, both Plato and Aristotle ultimately consider immaterial being superior to material being because the former is associated with divinity and activity, while the latter is associated with passivity and is dependent on the former to bring determinate beings into existence.

From this metaphysical foundation, we can now discuss Plato's and Aristotle's respective accounts of the soul/mind and the body, both of which subordinate the latter to the former. For Plato, the soul is an immaterial and immortal being associated with divinity, which is inherently active insofar as it is essentially living (Phaedo 105c–106e), self-moving (Phaedrus 245c–246e), and/or intelligent (Phaedo 70b; Republic 439c–d; Timaeus 30b, 46d). The body, in contrast, is material, perishable, non-divine, and inherently passive insofar as it is in itself devoid of life and motion. For a body qua material being to be alive or in motion, then, it requires the direct or indirect influence of a soul qua immaterial being — direct when a soul bestows life or motion on a body from within that body and indirect when a body is put in motion by other external bodies whose ultimate source of motion is a soul (there being both individual souls and a world soul, the former being contained within the latter; see Timaeus 29e–30d, 34b–c). Similarly, for Aristotle, the soul is a special kind of form qua immaterial being which bestows life functions on certain kinds of matter, namely those with the potential to possess such functions. Without a soul qua form, there can be no life in any body qua parcel of matter (On the Soul II.1; Metaphysics घ.10.1035b14–16). Both thinkers also, in their mature philosophies, draw a distinction between rational (i.e., mental) and non-rational dimensions of the human soul.Footnote ⁸ Plato divides the soul into (bodily) appetite, spirit (namely, passion), and reason (Republic IV). Aristotle splits the soul up into nutrition, sensation, appetite, and reason through deliberation and contemplation (On the Soul II.1–2; Nicomachean Ethics I.7; VI.5–8). Concerning the soul's immortality, Plato and Aristotle consider the non-rational dimensions of the soul perishable through their dependence on the body and the rational (mental) dimension imperishable and separable from the body (Republic 610d–612a; Timaeus 41a–46e; On the Soul II.1.413a6–7; III.4.429a22–429b4–5, 5.430a18–25; Metaphysics Λ.3.1070a22–25). Therefore, for both Plato and Aristotle, the soul/mind qua immaterial being is ontologically superior to the body qua material being because the former is by nature active and imperishable and plays a superordinate role over the body, the latter of which is by nature passive and perishable.

In the realm of ethics, we find the same sort of relationship of inequality and hierarchy between mind and body. For both Plato and Aristotle, the non-rational dimensions of the soul linked to the body should be subordinate to the rational (i.e., mental) dimension of the soul. Happiness as a life of virtue involves reason ruling over appetite and spirit in the Platonic soul (Republic IX) and nutrition, sensation, and appetite in the Aristotelian soul (Nicomachean Ethics I.7, 13; II; VI).Footnote ⁹ For Plato, happiness, to some extent, requires us to distance ourselves from bodily concerns for the sake of intellectual endeavours. He links vice and unhappiness to materialistic obsession qua imprisonment and the subordination of reason to the body (Phaedo 80d–83e; 108a–c; Republic 611b). Virtue and happiness are conversely found in contemplation of Forms qua immaterial beings, namely the Forms of Good and Beauty, the philosopher qua lover of wisdom moving from intense love for a single beautiful (perishable) body, to love for the beauty of bodies in general, souls, knowledge, and then finally love for the (eternal) Form of Beauty itself (Republic V–VII; Symposium 204a–205a, 210a–212a). While there is debate about whether the truly virtuous and happy lover has no concern for bodily things whatsoever (e.g., Nussbaum, Reference Nussbaum1979) or merely a rationally transformed and moderate conception of the value of such things (e.g., Sheffield, Reference Sheffield2006), the fact remains that in Plato's ethical framework, bodily goods are inferior to mental ones. Care for the body may be necessary and important, but only for the sake of promoting happiness as intellectual flourishing.

Similarly, for Aristotle, we care for the body through moral virtue (i.e., contextually balanced dispositions with respect to affections and actions; see Nicomachean Ethics II) because we cannot realize our deliberative and contemplative capacities and virtues if the body is ill. Moreover, even though practical wisdom (i.e., excellent deliberation about contingent matters concerning the role of the body, affections, and actions in achieving happiness) is an intellectual virtue and intrinsically valuable (and thus arguably constitutive of some degree of happiness), it is nevertheless also instrumentally pursued for the sake of promoting theoretical wisdom. Theoretical wisdom involves contemplation of eternal truths concerning God, the heavenly bodies, and various genera and species in nature (see, e.g., Metaphysics, On the Heavens, and Physics). Ethically, theoretical wisdom is considered to be exclusively intrinsically valuable, the closest approximation to the activity of God qua immaterial intellectual being, and constitutive of the highest happiness by virtue of its comparative distance to perishable bodily concerns (Nicomachean Ethics VI.5–8, 12–13; X.7–8).

For both philosophers, in other words, happiness is primarily an intellectual condition, the body only having value insofar as it promotes the rational (and most divine) dimension of the soul qua immaterial being. In sum, by virtue of their association of divinity, activity, and rationality with the immaterial and the material with the absence of such things, Plato and Aristotle consider immaterial and mental being ontologically and ethically superior to material and bodily being.

2.2 Epicurus and the Stoics

Epicurus and the Stoics, in contrast, are ontological materialists. For them, everything in reality is fundamentally extended, and anything that has causal power in the sense of being able to act or be acted on must be corporeal. Something incorporeal conversely cannot have causal power because there is no intelligible way in which it could affect or be affected by anything (Letter to Herodotus §67; Long & Sedley, Reference Long and Sedley1987, §§45A–C).Footnote ¹⁰

Epicurus endorses an atomistic account of reality. Fundamentally, there exists void as eternal and infinite empty space qua extended being, and within that space, there exists an infinite number of indivisible bodies (atoms) of various kinds with respect to size, shape, and weight. Atoms are in perpetual motion, and collisions between certain kinds of atoms form fixed relationships which constitute bodily composites, such as the eternal gods, our particular world (which is one among an infinite number of other worlds), celestial bodies, and natural things like rocks, dogs, and humans. Living things, e.g., humans, are constituted by two different kinds of atomic compounds: soul and body. The soul qua atomic compound consists of fine atoms, while the body consists of dense atoms. While they are distinct atomic compounds, the soul and the body nevertheless cannot exist independently of each other. They rely on one another to maintain the fixed relationship between their respective constituent atoms, and there can be no thought, feeling, or action for either compound when they are separated. The human soul and body are therefore mortal (Letter to Herodotus §38ff.; Letter to Pythocles §88ff; Long & Sedley, Reference Long and Sedley1987, §§4–15).

For the Stoics, reality consists of void, matter, and God, all three of which are eternal and extended in nature. Within void, the universe is constituted by God as an active body and matter as a passive body. God purposefully and rationally shapes the structure and order of the universe from within matter. Although they are distinct bodies, God does not exist separate from matter. Instead, they are eternally entwined, God being the soul of the universe and matter its body. Because God is a constituent of the universe, all individual things within the universe are part of God's soul and partake in Its rationality to some degree, if only by possessing a determinate essence and structure. In the technical sense, however, only beings with sensation and impulse (i.e., the capacity for self-motion, like God) possess a soul proper. Humans share in God's soul to the greatest degree among things because they also possess reason, and thus the ability to make judgements about how to act. While the Stoics grant the soul the ability to exist after the death of the body, it is not ultimately immortal because the soul is destroyed when the universe is inevitably destroyed (and then remade) by God (Laertius, Reference Laertius and Hicks1925, VII.132–160; Long & Sedley, Reference Long and Sedley1987, §§43–55). In both metaphysical accounts, then, divinity, activity, the soul, and rationality are associated with corporeal being. Non-extended being has no place in reality, and extended, but incorporeal, being has no causal power. Only bodies play a meaningful and active role in explaining the nature of things. For Epicurus and the Stoics, then, corporeal being is ontologically superior to incorporeal being, and the soul is neither immortal nor incorporeal.

Despite this ontological materialism, however, both Epicurus and the Stoics (like Plato and Aristotle) are ultimately committed to some form of ethical intellectualism, where mental things are superior to bodily ones. Epicurus conceives of happiness as the bodily pleasure of freedom from pain and the mental pleasure of freedom from disturbance (Letter to Menoeceus §§128–130). For the gods, this happiness is never-ending, while for humans it must be constantly replenished and it ceases with death (Laertius, Reference Laertius and Hicks1925, X.121). Epicurus also argues that there can be no pleasure and happiness, bodily or mental, without a body that is healthy or sufficiently unimpeded in its natural functioning (Cicero, Reference Cicero, Annas and Woolf2004, I.55) and that all pleasures, although not equal in value, are nevertheless by nature good insofar as they promote natural functioning (Letter to Menoeceus §129; Principal Doctrines VIII). From these details, one might think that Epicurus is an ethical materialist. Firstly, we know that the soul/mind and the body are both corporeal qua atomic compounds, and thus happiness as a natural state cannot be ontologically incorporeal. Secondly, Epicurus not only considers bodily pleasures intrinsically good and necessary for happiness, but also considers certain bodily pleasures constituents of happiness.

These features certainly indicate that Epicurus grants greater ethical value to the body than Plato and Aristotle (and, as we will see shortly, the Stoics), but other features show that, ultimately, he (like the others) thinks that the mind is more valuable than the body in the context of happiness. Practical wisdom qua mental virtue, for starters, is necessary for understanding the differing values of various kinds of pleasures with respect to achieving and maintaining happiness. Without the rational capabilities of the soul, the body would be unable to stably enjoy freedom from pain (Letter to Menoeceus §§131–132; Principal Doctrines V, XVIII, XX–XXX). As well, Epicurus considers mental pleasures more valuable than bodily pleasures because the former can refer to the past, present, and future, through recollection, reflection, and anticipation respectively, while the latter can only refer to the present. As a result, mental pleasures offer us greater resources in combatting bodily pains and/or mental disturbances than bodily pleasures (Laertius, Reference Laertius and Hicks1925, X.137; Cicero, Reference Cicero, Annas and Woolf2004, I.55–56). For example, Epicurus on his deathbed was reportedly happy (Letter to Idomeneus), despite being in intense bodily pain from gastro-intestinal issues, because he was able to rely on mental pleasures to overcome pain through memories of past good moments with beloved friends and (arguably) the comforting anticipation that this intense pain would come to an end, if only in death (Principal Doctrines III–IV). In general, it is said that the Epicurean sage being physically tortured on the rack is happy, despite their physical suffering (Laertius, Reference Laertius and Hicks1925, X.118). This indicates that, while bodily pleasure is a genuine constituent of happiness, and may be strongly necessary in first achieving this state, bodily pleasure in itself is insufficient to constitute happiness and/or plays a less necessary and impactful role in maintaining happiness moving forward.Footnote ¹¹ Mental pleasure, conversely, is strongly necessary for achieving and maintaining happiness, and is largely sufficient for maintaining this state of being. Consequently, while Epicurus considers everything, including the mind, corporeal, he nevertheless follows Plato and Aristotle in considering mental goods more valuable than bodily ones. This makes him, at least, a weak ethical intellectualist.

The Stoics, in contrast, endorse a strong ethical intellectualism, one stronger in some sense than even Plato's and Aristotle's. For the Stoics, happiness consists in virtue as living according to our rational nature. They consider the only good virtue, where the mind uses its rational faculty well in line with mental health, and vice the only bad, where the mind uses its rational faculty poorly in line with mental illness. Everything else, most notably the body and its various states, is considered morally indifferent in the sense that such things play no necessary, sufficient, or direct role in happiness. At best, morally indifferent things like bodily health, illness, activity, pleasure, and pain can be useful tools in developing or expressing prior states of virtue, but one can be truly happy in their absence and their presence does not add to, or diminish, one's happiness whatsoever (Laertius, Reference Laertius and Hicks1925, VII.87–131; Long & Sedley, Reference Long and Sedley1987, §§56–67). In other words, while Stoic happiness is in general ontologically corporeal in nature, it is also nevertheless exclusively intellectual in essence. One simply needs to be rational to be happy, with the body (as something neither truly good nor bad) playing an inconsequential ethical role in living well. Despite their materialism, then, the Stoics offer the strongest form of ethical intellectualism, in the sense that goodness is restricted to the realm of the mental.

In sum, all four eudaimonistic philosophies are committed to ontological and ethical inequality and hierarchy between mind and body.Footnote ¹² On the one hand, Plato and Aristotle consider immaterial/mental being superior to material/bodily being by virtue of the former's association with divinity, activity, and rationality in the context of the universe and happiness. Epicurus and the Stoics, on the other hand, ontologically ground divinity, activity, and rationality in corporeal being, rendering the incorporeal inferior to the corporeal. Ethically, however, they both place mental things over bodily ones in the context of happiness. As we will see in the next section, Spinoza places himself in opposition to both materialism and intellectualism in the realms of ontology and ethics. In his eudaimonistic framework, immaterial/mental being and material/bodily being are non-reductively identical and thus equal in status.

4.1 The Absolutely Infinite (Representational) Power of Thought

The first problem is connected to what Melamed (Reference Melamed2013, p. 142) refers to as “Ideas-Things Parallelism.” In E IIP7, Spinoza argues that “[t]he order and connection of ideas is the same as the order and connection of things,” and in the succeeding corollary he further clarifies that “whatever follows formally [i.e., actually] from the infinite nature of God, all this follows from the idea of God with the same order and connection, as an object of thought in God.” There is, in other words, a strict correspondence between ideas and the things that constitute reality, meaning the idea of God (or the absolutely infinite intellect) qua immediate infinite mode of Thought, and the more particular ideas that are contained within this mode, perfectly mirrors and represents in its content God's infinitely many attributes (including Thought) and the causal orders of modes that follow from those attributes. In the realm of mind and body, this means that, for any given body, there is necessarily an idea that both corresponds with and essentially represents that body, and for every state of that body, there will be a corresponding idea of it (IIP12–13).Footnote ²⁹ Melamed (Reference Melamed2013, Chapter 6) also argues that (in conjunction with E IIP7S, that is, Inter-Attributes Parallelism), within the attribute of Thought, there is an idea of each neutral mode of God that makes up the fundamental causal order of everything, and each of these ideas has infinite aspects that represent the expression of this causal order under each attribute (IP16; IIP4).

Now, why does Ideas-Things Parallelism potentially undermine the previously demonstrated equality between thinking and extended being? The issue, as Spinoza's friend Tschirnhaus puts it, is that “the Attribute of thought is held to extend itself much more widely than the other attributes” (Ep 70/G IV 302). Spinoza attributes to Thought the power to represent all of reality as it is constituted by God's attributes and modes, and if Melamed is correct, we can also say that each idea of a neutral mode has infinite aspects which are ideas of how this mode is expressed through each attribute. In fact, Melamed (Reference Melamed2013, pp. 183–185) also notes that Spinoza describes the immediate infinite mode of Thought as “absolutely infinite intellect” (Ep 64/G IV 278), meaning that from the idea of God “infinite things [i.e., ideas representing modes of God] follow in infinite ways [i.e., through attribute-relative aspects of these ideas]” (E IIP4). God qua substance is the only other thing referred to as “absolutely infinite” (IDef.6). Extension, and the attributes in general, are described as merely infinite in their “own kind,” that is unrestricted in their distinctive expression of being because each does not actually possess all possible being (IDef.6Expl., IP16Dem.). Admittedly, Thought qua attribute is only formally infinite in its own kind, and not absolutely infinite, but representationally it is absolutely infinite because it can refer to all possible being through its distinctive power of thinking. Extension's distinctive power (and presumably the power of the other hypothetical attributes) does not possess this absolute infinity. As a result, Thought seems to be more powerful, or to express more being, than Extension and possibly any other attribute. In fact, when Spinoza says that “God's [NS: actual] power of thinking is equal to his actual power of acting,” he is not referring to the power of Extension alone, but instead to the power of all of God's attributes: “I.e., whatever follows formally from God's infinite nature” (IIP7C). In other words, Thought is not equal to Extension alone — Thought is apparently equal in power to all of the attributes together because it represents all of them and their respective modes. Spinoza is not an idealist (in a reductive sense) because Thought does not exist prior to or cause/sustain Extension and the other attributes, but its expression of being appears to be more plentiful than any other attribute, which leads Melamed (Reference Melamed2013, Chapter 6.7) to conclude that Thought has “priority” as an attribute and Spinoza is a dualist of “Thought and Being.” It would seem, then, that extended being (and any other kind of being) is ontologically inferior to thinking or intellectual being, and thus, contrary to my abovementioned argument, mind and body are not truly equal.

Ultimately, I do not think these features concerning Thought undermine my reading of Spinoza, nor do I think Spinoza is rightly called a “Thought-Being dualist.” I caution the reader to be careful not to arbitrarily consider one kind of power superior to another. Just as Thought is not inferior to Extension because the former cannot exist spatially or be real in a tactile sense, so too Extension (or any other attribute) is not inferior to Thought because the former cannot represent things. Spatiality and representation are equally real and fundamental expressions of being (namely, substance). Admittedly, Thought is able to refer to all of reality in a way that no other attribute can, and it does possess a kind of absolute infinity relative to its domain of power. However, it is simply the nature of representation to refer to reality. Spinoza himself cautions us against judging the perfection of things based on features that are not inherent to their respective natures: “the perfection of things is to be judged solely from their nature and power” (IApp./G 83; see also IVPref. and Ep 19 and Ep 21). A bird is not ontologically inferior to a human being because the former lacks opposable thumbs. A human is not inferior to a bird because the latter has wings. Someone born blind is not inferior to someone born sighted. In each case, something cannot be less perfect because it lacks some feature foreign to its nature.Footnote ³⁰ And these are examples of things with much more in common than the attributes of Thought and Extension, the latter of which are wholly conceptually/causally distinct in their expression of being. Based on this passage, we can infer that Spinoza, in principle, would not condone speaking of any attribute as inferior or superior to another, meaning that no attribute is inferior to Thought because the former cannot refer to all of reality — this is a feature only intelligible through the representational power of thinking, which cannot be appropriately compared to the power of Extension or any other attribute.

Even if an argument could be made for legitimately considering Thought ontologically superior to the other attributes, this simply qualifies the ways in which thinking and extended being are equal. The fact remains that E IIP7S establishes an equality of identity between Thought, Extension, and all the other attributes. There can be no instance of thinking without an instance of extension, and vice versa. Thought's expression of representational power strictly corresponds with the expression of every other attribute's distinctive power because they are merely different aspects of the same underlying power. Furthermore, the human mind and human body have no conceptual or causal connection to the modes of other attributes, so Thought's representation of all of reality has little impact on our bodies and minds. What is relevant to us ontologically (and, as we have seen, ethically) is the identity of mind and body — the fact that mental power and bodily power strictly exist, flourish, and stagnate together. All the apparent ontological supremacy of Thought entails is that mind and body are not equal in every possible sense, but the qualified equality of identity that they do possess is far from trivial. Consequently, even on a reading of Spinoza as a Thought-Being dualist, Spinoza's commitments to mind-body equality remain true and distinctive in an eudaimonistic context.

4.2 The Eternal Dimension of the Mind

The second potential issue, in the ontological context, is the eternal dimension of the mind. Spinoza specifically argues that a part of the mind (namely, its essence as the idea of a particular material ratio of motion/rest) can survive the death of the body because it is eternally contained within the attribute of Thought (E VP2–23). If the mind possesses eternal existence that the body does not, then this would also indicate an ontological inequality between body and mind, with the body being inferior to the mind due to the former's exclusively mortal existence. Wolfson (Reference Wolfson1934, Volume II, pp. 293–296) takes this view, arguing that the body is only eternal insofar as its essence is an object of thought — making the essence of the body at best representationally, but not ontologically, eternal.Footnote ³¹

Other scholars (Della Rocca, Reference Della Rocca2008, pp. 257–258; Garrett, Reference Garrett2018, pp. 244–252; Nadler, Reference Nadler2006, pp. 262–265), however, argue that, by virtue of E IIP7S, it makes more sense to say that both body and mind have eternal parts, since they are identical, and thus the eternal part of the mind must have a bodily counterpart. Wolfson's error is failing to appreciate that the essence of the mind receives its eternity from being contained in Thought, and it represents the essence of the body as something eternally contained within the attribute of Extension (E IIP8, IIP45S; VP29S). Aaron Garrett (Reference Garrett2003, pp. 194–197) speculates, I think plausibly, that Spinoza only argues for and emphasizes the eternal dimension of the mind because his traditionally and religiously minded readers were primarily concerned with the immortality of the mind/soul, not the body. Spinoza wants to correct their understanding of what immortality for the mind actually consists in, namely an eternal essence qua mode devoid of imagination, memory, and personality (E VP21). It is thus more consistent with Spinoza's doctrines to consider mind and body equally eternal in the same respect because their essences equally follow from the eternal nature of their respective attributes.Footnote ³²

4.3 The Absence of an Explicit Corporeal Counterpart to Intellectual Love of God

The third problem concerns the fact that Spinoza seemingly never describes virtue and happiness in bodily terms. He only seems to describe them in intellectual terms. Virtue and happiness are equated not only with adequate causality in general, but more specifically and concretely with mental adequate causality in the form of adequate knowledge (IVP23–24). Adequate knowledge is constituted by ideas that are rationally ordered (VP10) by the mind so as to reveal the necessary truth, or certainty, of their content (IIP29S, 40, 44; IIIP1), meaning that the mind is responsible for its own understanding. Conversely, inadequate knowledge is constituted by “confused” and “fragmentary” ideas (IIIP1; VP3) that are constituted by the circumstantial and haphazard ways in which one has interacted with things in the world through sensory experience, meaning such ideas follow partly from the causal power of external things rather than from the intellectual resources of the mind alone (IIP29C–S; 40).Footnote ³³ With this epistemological framework in mind, Spinoza argues that “we know nothing to be certainly good or evil except what is really conducive to understanding or what can hinder understanding” (IVP27). It would seem that goodness is ultimately grounded, then, in the promotion of mental striving and power, and not both mental and bodily striving/power. In line with this point, Spinoza explicitly describes blessedness (beatitudo), the highest good (summum bonum), and the highest happiness (summum felicitas; see E IVP28/G II 228, IVApp.4/G II 267) as “intellectual love of God” (Amor Dei intellectualis; see VP32C), thereby equating this state of being with mental power, virtue, and pleasure (VP25–27, VP35–36, VP42). Does this mean that Spinoza considers happiness a purely intellectual good?

Miller's (Reference Miller2015, Chapter 5.6.3) answer to this question is “yes.” He argues that happiness has no bodily counterpart because Spinoza considers all bodily goods external in nature. Every conceivable bodily good, like “food, drink, exercise, [and] health” is external because such things are “not entirely due to us” (Miller, Reference Miller2015, p. 200). In other words, anything that is beneficial to the body must come from outside of it and hold only circumstantial instrumental value, which is in stark contrast to the internal and intrinsic goodness of intellectual activity qua adequate causality that the mind enjoys with intellectual love of God. Miller concedes that this conception of bodily goods is in tension with Parallelism (E IIP7 and IIP7S).Footnote ³⁴ However, he thinks that a solution can be found in the distinction Spinoza draws between what is in “human power” and what is “outside” of human power, even if Spinoza himself had not quite solidified his thoughts on this matter (IVApp.32; see also IIIDef.2; IVP18S, IVApp.2). What is in human power is reason, which fits with Spinoza's identification of the highest good with intellectual love of God, the highest intellectual power and pleasure. Conversely, bodily factors are (at least partly) outside of human power, which explains why the body has no intrinsic good. The extrinsic and circumstantial nature of bodily goods is thus the reason that the body is not a constituent of the highest good, according to Miller.

Miller is correct that Spinoza draws an important distinction between what is and is not in our power, as evidenced by the distinction between activity qua adequate causality and passivity qua inadequate causality (IIIDef.2). However, there is little reason for mapping this distinction onto the relationship between mind and body in general or restricting virtue to intellectual power. As Miller himself admits, IIP7S entails a strict correspondence, and in fact identity, between mind and body. One's essential self-preservative striving, power, and subsequent pleasures and pains are equally mental and bodily in nature. And since virtue just is one's essential power considered in itself, virtue is also equally mental and bodily in nature (IVP8).

Miller's point is that, while the mind has a bodily correlate, the body by nature possesses a passivity that the mind does not, which is why all possible bodily goods are external. It is true that Spinoza's description of the body emphasizes its causal receptivity: “[w]hatever so disposes the human Body that it can be affected in a great many ways” (IVP38). There are two things to note here, however. Firstly, in IVP38, Spinoza also emphasizes the body's active causal power: “or renders it capable of affecting external Bodies in a great many ways.” In fact, we might say that this description implies that a body's causal power fundamentally lies in having as much of a causal role (as cause or recipient) in phenomena as possible, similar to the way that God qua substance plays an absolute causal role in everything because It is every cause and is the recipient of every cause (IVP14–15, IVP18). Secondly, this causal dynamic is also not restricted to the body. In IVP18S/G II 223, Spinoza asserts that “our intellect would of course be more imperfect if the Mind were alone and did not understand anything except itself” and in IVApp. 27 he references the “knowledge we acquire from observing [external things] and changing them from one form into another.” In other words, the mind, like the body, can be enriched by external things, and thus possesses external goods of its own. There is also the more fundamental fact that the mind necessarily possesses inadequate ideas, which are representative of its inevitable passivity to some degree (IIIP1). These passages, in turn, indicate that intellectual power also involves receptivity, meaning that the mind is not wholly internal. This makes sense because by virtue of IIP7S the activity and passivity of a being is attribute-neutral — it does not presuppose only one attribute, but all of them (IVApp.; VP40). Any degree of passivity that the body possesses, the mind will necessarily possess, relative to their respective natures. What is in our power is both mental and bodily, and what is not in our power is that which is distinct from our mind and body (IVP45S; VP39).

Moreover, after arguing for the intrinsic goodness of understanding, Spinoza goes on in IVP38Dem. to argue that “what disposes the Body” to affect and be affected “is necessarily good,” meaning that the body is not neglected in this ethical conversation. Nor is the power and goodness of the one treated as separate from the other: “[A]s the body is more capable of being affected in many ways and of affecting external bodies in many ways, so the mind is more capable of thinking” (IVApp.27; see also IVP45S; VP39). It is also important to remember that mind and body are identical because Thought and Extension are identical constituents of God, and in turn my mental/bodily power is a particular manifestation of God's thinking/extended power, which is why Spinoza says that the more adequate causal power we have, the more we directly partake in the divine (IIP49S/G II 135; IVP45S). Consequently, pace Miller, by virtue of Spinoza's commitments to Substance Monism (IP14), the Conatus Doctrine (IIIP6) as the foundation of his ethics, and Inter-Attributes Parallelism (IIP7S), the body does indeed possess an ultimate intrinsic good, just like the mind: self-affirmative and adequate causal power/pleasure. We are ultimately talking about the same power, pleasure, and intrinsic good in the context of virtue and happiness — mind and body are simply two conceptually different, but co-extensive, aspects of these underlying things.

Why then does Spinoza consistently mention the mind, but not the body, when discussing virtue and happiness? And, if adequate knowledge and intellectual love of God express the intellectual dimension of virtue and happiness, what precisely expresses the physical dimension of them? One potential explanation to the first question is Spinoza's comment that “no one has yet come to know the structure of the Body so accurately that he could explain all its functions” (IIIP2S; see also Ep 83). Spinoza is obscure about what bodily power and goodness consist in because he believes that the science of his time (and he himself) still has a long way to go in fully explaining the nature of the human body. In fact, Spinoza clarifies that his philosophical project in the Ethics is specifically aimed at “the highest blessedness” of the mind (E IIPref.). Furthermore, in VPref./G II 276, he says that “it does not pertain to this investigation [in the Ethics] to show how the intellect must be perfected, or in what way the Body must be cared for, so that it can perform its function properly. The former is the concern of Logic, and the latter of Medicine.”Footnote ³⁵ While Spinoza covers a lot of diverse philosophical ground in the Ethics, this passage shows that he does not take himself to be offering answers about everything, even in the realm of achieving blessedness. He opts for not getting into the precise and complex details of promoting mental well-being through logic and bodily well-being through medicine. This makes sense particularly in the context of medicine, since Spinoza thinks that far more scientific work must be done to adequately understand the body. In the Ethics, Spinoza provides us with metaphysical, physical, epistemological, ethical, and political foundations, not a comprehensive account of everything within these domains of knowledge. Spinoza, while likely self-assured about much of his knowledge, is nonetheless not arrogant enough to think that there is nothing more for him or us to know than what he presents in this treatiseFootnote ³⁶ (with his detailed, and potentially evolving, discussions of socio-political matters in the Theological-Political Treatise and the Political Treatise being prime examples of further work done in this regard).Footnote ³⁷ He also does not argue that the highest virtue and highest good consist solely in adequate knowledge or intellectual love of God. What Spinoza actually says is that this form of knowledge/pleasure is the “Mind's greatest good” (IVP28) and “greatest virtue” (VP25). These points tell us only that his main ethical concern in this text is the mental dimension of blessedness, not that there is no bodily dimension to this causal and affective state.Footnote ³⁸ Admittedly, Spinoza might personally care more about the ethical role of the mind than the body, but, as I have shown above, his actual doctrines do not entail the ontological/ethical priority or superiority of the mind over the body.

Let's move to the second question: what does the bodily dimension of happiness concretely involve? Kisner (Reference Kisner2011, pp. 78–79) identifies this bodily good with brain activity and Susan James (Reference James, Kisner and Youpa2014, pp. 147–159) identifies it with the ability to physically act in parallel to one's knowledge. Affectively, Firmin DeBrabander (Reference DeBrabander2007, pp. 60–62) describes cheerfulness as the bodily correlate to intellectual love of God qua mental pleasure (E IVP42). Spinoza himself never makes it clear, but all three answers are plausible. In fact, I think that these three interpretations are compatible with each other, brain activity being a central manifestation of the general physical activity that parallels one's knowledge and cheerfulness being the affective aspect of such physical activity insofar as it pertains to the body as an empowered whole. Even if these potential responses are incorrect or Spinoza had not yet decided what the true good of the body is precisely (with the Ethics providing a solid foundation for further inquiry), the fact remains that the identity between mind and body, in conjunction with the conatus as the foundation of Spinoza's ethics, entails that mental power and bodily power are equally good and equal constituents of happiness, because they are simply two aspects of one ultimate good: self-empowerment.Footnote ³⁹

Ultimately, then, the representational power of the attribute of Thought, the eternal dimension of the mind, and Spinoza's description of happiness in intellectual terms are all compatible with his commitment to the ontological and ethical equality of mind and body, when we take into consideration certain key doctrines (namely, Substance Monism, Inter-Attributes Parallelism, and the Conatus Doctrine) within his philosophical framework.