My work extends throughout ancient Greek and Roman philosophy, primarily focusing on ancient conceptions of life, soul, mind, and personhood. Ancient philosophers made use of these conceptions in varied explanatory contexts (e.g., ethical, scientific, theological), and were often strikingly attentive to the differences between these contexts. Hence, I approach these conceptions not as isolated theories that emerge ex nihilo, but as products of holistic thinking that are responsive to diverse philosophical goals. I trace both how they arise from a thinker’s broader metaphysical, epistemological, and cosmological commitments, and how they influence ‘ways of life’, shaping a thinker’s practical ethical and political thought. I concentrate on Aristotle’s conceptions of soul, mind, and life, their place within his broader philosophical program, and their implications for his accounts of perception, desire, and reason.
These interests led to my dissertation, Aristotle’s Divided Soul. I provide a novel interpretation of Aristotle’s conception of ‘parts of soul’ (moria psuchēs) in his De Anima and related biological and psychological works: how a soul could genuinely both have parts and be unified, and how Aristotle’s account emerges out of his hylomorphic metaphysics, and critiques of his philosophical predecessors. Interpreters have failed to explain how Aristotle can maintain two philosophically attractive and textually grounded claims: that there are multiple discrete parts of soul, and that soul is the unified and unifying form (eidos) of the living organism. Contrary to most interpreters, I argue that both claims are genuinely endorsed by Aristotle and, when correctly understood, crucial to the project of De Anima as a whole. First, psychic parts are not spatial parts, but are instead the definitionally basic capacities or powers of an organism (nutrition, perception, intellect). These basic capacities, in turn, provide the explanatory foundation for understanding all other vital capacities. Second, Aristotle formulates a sophisticated account of psychic unity, according to which psychic parts are ‘present potentially’ within the soul: the soul is no mere aggregate of parts, but is actually and essentially a whole, even while having parts.
Further, I argue for the relevance of these ancient conceptions of soul and life throughout the history of philosophy, contemporary philosophy of mind, and moral psychology. I consider how we divide the soul or mind, how this has been influenced by Greek thought, and the diverse uses to which these divisions have been used—e.g., to distinguish rational from irrational, conscious from unconscious, human from animal. Further, I investigate how theoretical and scientific approaches to the soul, mind, or person (e.g., as in De Anima or contemporary cognitive science) relate to with ordinary approaches, or ‘folk psychology’, which are found more often in ethical or political contexts.
Book Project: Aristotle’s Divided Souls: Parts of the Soul in Aristotle’s Psychological, Biological, and Ethical Thought
In modern ethics and philosophy of mind, we often find recourse to some notion of elements, modules, or faculties of a person or mind—in ancient Greek terminology, ‘parts of soul’. An ethicist might distinguish between elements responsible for rational and irrational desires; a cognitive scientist might distinguish between modules responsible for basic perceptual activities and higher rational functioning. The relationship between the parts discussed in these two philosophical projects, however, is often left unclear, or even the site of substantial tension. Aristotle, I argue, self-consciously engages in both sorts of projects, and so provides a rich example of this tension and a sophisticated response to it. He offers competing conceptions of psychic parthood in his practical-ethical works and in his theoretical-biological works. In the former, he divides the soul into rational and irrational parts; in the latter, he rejects this as methodologically unsound, opting for his infamous nutritive-perceptual-intellectual division. In the first part of this project, I detail these two pictures, and so provide a comprehensive treatment of his conceptions of psychic parthood. On the one hand, Aristotle offers in his ethical works a commonsense, anthropomorphic conception of the soul, according to which the soul is comprised of two agent-like parts that vie for control over the behavior of individuals; psychic unity is the ethical achievement of a virtuous agent. On the other hand, he offers in DA a metaphysically sophisticated picture, according to which the soul is comprised of ‘potentially present’ logical parts; psychic unity is not an achievement, but a condition of the existence of souls. In the second part of the project, I argue that the differences between these pictures of psychic parthood reflect a difference between Aristotle’s conception of the goals and standards of practical and theoretical inquiries. In practical inquiries (like Aristotelian or contemporary ethics), the standard for correctness is a claim’s practical contribution to moral development. In theoretical inquiries (like Aristotelian psychology or contemporary cognitive science), the standard is metaphysical and logical consistency, and a claim’s ability to universally explain the relevant empirical phenomena. Hence, I contend that Aristotle can endorse two different divisions of soul, insofar as they play distinct roles in two distinct sorts of inquiries.
Papers (drafts available by request)
“Aristotle’s Unified Soul: The Figure-Soul Analogy and It’s Context” (Forthcoming in Journal of the History of Philosophy)
I offer a novel reading of Aristotle’s account of psychic unity, according to which the soul is a non-aggregative unity that is prior to its parts. Aristotle’s anxieties about the soul’s unity arise because of an ‘actualist assumption’: psychic parts are actually distinct entities, which are brought together by an external unifying cause. To reject this assumption, Aristotle describes an alternative conception of parthood (‘potential parthood’) within an analogy between souls and geometric figures. As a triangle is present potentially within a square, so psychic parts are present potentially within the whole soul. This alternative picture undermines the actualist assumption, indicating that the soul is no mere aggregate of parts, but is actually and essentially a whole, which is prior to its parts
“Aristotle on Perceptual Discrimination: Perception as Substance and as Limit” (R&R)
I argue that Aristotle’s claim that perception is like a ‘point’ constitutes a rejection of Literalist or naturalist conceptions of perception. Having argued that perception must be unified, Aristotle initially entertains that the unity of perception resembles that of a normal material substance—“undivided in number, but divided in account.” Yet, because this substance model fails to explain the discrimination of opposites (e.g., sweet and bitter), Aristotle discards the substance model, instead claiming that the unity of perception resembles that of a point. Aristotle, I argue, thereby affirms an anti-Literalist account of perception, and rejects accounts that model perception on the structure of ordinary material objects
“The Parts and Science of Soul: Aristotle’s Critique of Platonic Bipartition and Tripartition” (Under Review)
I reconstruct Aristotle’s criticisms of Platonic moral psychology in DA III.9: a tripartition into appetite, spirit, and reason, and a bipartition into rational and nonrational parts. At the heart of Aristotle’s criticisms, I contend, lies a question about what it means for psychic division to be scientific—whether psychic parthood has any role within DA’s theoretical psychology, beyond metaphor. Aristotle claims that bipartition and tripartition do not live up to the standards of a scientific psychic partition: they offer no principled explanation of the structure of the soul, instead implying that there are indefinitely many psychic parts. While bipartition and tripartition have roles in other explanatory contexts (e.g., ethics), they have no place within a theoretical account of soul.
“Aristotle’s Worms and the Psychology of the Timaeus” (Under Review)
I formulate a novel interpretation of Aristotle’s rejection of the conception of psychic parthood in Plato’s Timaeus. This conception holds that psychic parts are spatially separable and operate within distinct bodily regions. A close reading of Aristotle’s arguments reveal both a subtle criticism of the Timaeus and a rich picture of the relationship between Aristotelian and Platonic psychologies. While both psychologies seek to explain the soul’s relationship to the body, Aristotelian psychology is committed to a deeper unity of soul than can be accommodated within Platonic psychology.
“Aristotle and Additive Theories of Rationality” (In Progress)
The additive theory of rationality (e.g., Velleman, 2000; Evans 1982) is a widespread conception of mind, according to which human perceptual and desiderative systems are shared with animals, and so are separate from any distinctively human rational systems. I argue that Aristotle rejects any such picture of mind or soul, formulating in De Anima I.5 a sophisticated precursor to the contemporary “Unity Problem” (Boyle, 2014): with additive theories of rationality, one faces difficulties in regarding the mind as a single subject of which desires, perceptions, and rational choices or thoughts are predicated. Aristotle contends that an additive theory of soul, which posits separate desiderative and intellectual parts of soul, similarly lacks the resources to account for the unity of the soul, and so must be rejected.
“Why Aristotle’s Soul Needs Parts” (In Progress)
Despite recent renewed interest in Aristotle’s conception of “parts of soul” in De Anima, some scholars contend that the Aristotelian soul lacks parts, and that his use of “part of soul” is merely metaphorical. I defend the existence of Aristotelian psychic parts, arguing that Aristotle must be committed to the existence of psychic parts, given his other metaphysical and psychological doctrines. This commitment emerges from his more fundamental commitment to the “homonymy of life”. According to this doctrine, ‘life’ lacks a single univocal definition and living is constituted by multiple heterogenous activities. Hence, animal and human souls are made up of multiple discrete capacities (nutrition, perception, and intellect). Because these capacities are irreducibly many, animal and human souls must themselves be internally complex and divisible into parts. Consequently, any interpretation of De Anima must recognize the central role that psychic parthood plays in Aristotle’s theory of soul.
There once was a man named Aristotle/Whose views on the soul were colossal/He said it’s divided/Into parts, he decided/And the rational part was the apostle
Rory Hanlon 