Philosophers in antiquity never concealed their nervous attention to the elusive nature of material objects of perception. This elusiveness was quickly recognized as a genuine threat for the kind of robustness in knowledge that philosophy seeks to achieve. The only difference among Greek philosophers in this regard was that some of them found more joy in confronting this threat than others. Among the former group, one can arguably count Heraclitus, Protagoras, Gorgias, the Cyrenaics, Pyrrho and his followers, as well as the Academics. Depending on how one chooses to interpret the history of philosophy, the epistemic optimism of the Aristotelian or Stoic kind stands out as an exception rather than the norm. Plato, for his part, undertook an extensive examination of the metaphysical origins and the epistemological challenges posed by this troubling aspect of reality, a phenomenon we now discuss under the concept of “indeterminacy.”
Ugo Zilioli’s book explores this ancient strand of philosophical attention to the metaphysical indeterminacy of things, which manifests in two primary forms: eliminativism and nihilism (the latter being a radical extension of the former). Broadly understood, eliminativism about material objects is the metaphysical view that analyzes these objects as ultimately being eliminated “as determinate, ontologically stable items of the material world, or indeed eliminated tout court” (p. 1), despite appearances to the contrary. The book aims to trace the genealogy of this unorthodox metaphysical view in ancient Greek philosophy through a philosophical reconstruction, focusing on Protagoras (chs. 1–2), Gorgias (ch. 3), Pyrrho (ch. 4), and the Cyrenaics (chs. 5-6). In this sense, the book aligns with the line of research initiated by Richard Bett (2000) in his seminal work on Pyrrho. However, not only does Zilioli substantially broaden the scope of his research well beyond Pyrrho but he also introduces an original perspective by means of his innovative methodological approach. Drawing on the rich and sophisticated tools of comparative philosophy, Zilioli establishes analogies with the parallel doctrines of Vasubandhu and Nāgārjuna in Buddhism, to shed further light on his own analyses of Protagoras and Gorgias in the central chapters of the book. The Pyrrho-Buddhism affinity has also been studied before, but Zilioli brings fresh insights to this topic as well.
According to Zilioli, ontological eliminativism finds one of its most comprehensive expressions in the so-called “Secret Doctrine” that Plato attributes to Protagoras in the Theaetetus. In Chapter 1, Zilioli traces the dialogue’s progression to show that Protagorean relativism gains full philosophical significance when interpreted alongside the Secret Doctrine. Zilioli demonstrates that when it is conjoined with the basic tenets of the Secret Doctrine, Protagorean relativism as a theory of perception transforms into a strong form of ontological eliminativism. Rooted in the ontology of Heraclitean flux, the Secret Doctrine leads to the conclusion that the main outcome of Protagoras’s relativism is a metaphysical view in which “not only perceiving subjects but also objects of perception are ontologically indeterminate. […] Indeed, and strictly speaking, there are neither actual objects nor real subjects in the perceptual process.” (p. 23). Zilioli concludes that in the ultimate version of the Secrete Doctrine, “material objects (such as things and people) become ontologically redundant” (p. 33). Chapter 2 elaborates on this perspective further. Drawing on the Buddhist philosopher Vasubandhu’s ontology of dharmas, Zilioli develops a solution to a particularly challenging problem to which, according to a recent interpretation by Christopher Buckels (2016), the Protagorean doctrine is vulnerable. (While this chapter may be easier for those familiar with Secret Doctrine scholarship, Zilioli ensures accessibility for a broader audience.) The issue in question concerns the ontological status of material objects as understood within the theory of perception implied by the Secret Doctrine. In the Protagorean framework, perception involves the interaction of two “slow” motions—one from the perceived “object” and the other from the perceptual organ—producing two “twin” swifter motions: the particular perceptual quality and its corresponding particular perception. In his own interpretation, Buckels proposes a peculiar theory of tropes as the most plausible reading of this idea. However, Buckels argues that even tropes fail to deliver the desired eliminativist ontology for material objects that is somehow inherent to the Secret Doctrine. Tropes appear to presuppose an objective basis for those powers that produce them and ultimately form the bundle of sensibles we perceive as objects. Zilioli’s solution to this problem aligns with the goals of the Protagorean doctrine and offers greater simplicity. Drawing on parallels between the Protagorean doctrine and Vasubandhu’s dharmas—fundamental yet ontologically elusive elements— Zilioli argues that no distinction is needed between tropes and their generative powers, as dharmas function as both, without losing their radical ontological elusiveness.
Chapter 3 expands the discussion to nihilism. In the Conclusion, Zilioli examines how some forms of eliminativism can collapse into nihilism. This chapter, however, focuses on exploring how certain ideas from Gorgias and the Buddhist monk Nāgārjuna might suggest nihilism. Methodologically, Zilioli argues that interpreting one thinker in terms of nihilism justifies a similar interpretation of the other. In On What is Not, Gorgias develops antinomies on generation, change, motion, divisibility, plurality, and monism, concluding that nothing is. If we focus on the content of the text rather than Gorgias’ rhetorical or dialectical aims, his arguments could be seen as endorsing nihilism. Zilioli argues that Nāgārjuna’s philosophy of emptiness shows a great degree of analogy to Gorgias’ arguments and can be interpreted similarly. (In fact, Zilioli urges readers to consider that both philosophers may have intended to endorse nihilism with these arguments.) According to Nāgārjuna’s philosophy of emptiness, all things are empty in the sense that they are all devoid of intrinsic essence. The nihilist conclusion drawn from this is that nothing without intrinsic essence truly exists. Like Gorgias, Nāgārjuna constructs similar arguments on generation, change, eternity etc. to support this nihilistic conclusion. Despite their similarities as shown by Zilioli, the philosophers’ specific reasonings in certain arguments also reveal some differences. For example, their arguments against change are more alike than their arguments against eternity. Zilioli’s thesis could then be reframed as proposing that Gorgias and Nāgārjuna share argument “places” leading to nihilism, allowing their reasoning to be classified as nihilistic argument “topoi”, rather than directly comparing their arguments.
Chapter 4, on Pyrrho, is the last to adopt a comparative perspective with Buddhist philosophy. Zilioli begins by defending the metaphysical reading of the “Aristocles passage,” the most detailed source on Pyrrho’s thought. In the metaphysical reading, Pyrrho sees things as undifferentiated, unstable, and indeterminate, echoing the Buddhist ontology of dharmas. There is a considerably advanced literature on the affinities between Pyrrho’s outlook and early Buddhism. The novelty of Zilioli’s approach lies in reframing these affinities by extending the genealogy of Pyrrho’s metaphysics back to the ontology of the Secret Doctrine and the semantic indeterminacy that arises therefrom. Consequently, Zilioli argues that Pyrrho was “likely to have taken inspiration for his metaphysical outlook in the context of ancient Greek philosophy” (p. 81) and “to have ventured to India already philosophically prepared for his radical view of reality, just to discover that the same view was adopted by other thinkers such as the early Buddhists”. (p. 82). Thus, Zilioli offers a distinct alternative to existing studies on Pyrrho’s connections to Buddhism.
In Chapters 5–6 on the Cyrenaics, Zilioli again presents a metaphysical reading as an alternative to the skeptical interpretation of the Cyrenaics, while also responding, especially in the notes, to critics of his earlier work The Cyrenaics (2012). In the skeptical reading, the Cyrenacis shun from making an inference from the infallibility of private affections to the existence of external world objects as their cause. In this view, they refrain from any commitment to a metaphysics of the external world. Zilioli claims the opposite: he thinks that the epistemological subjectivism of the Cyrenaics is rooted into radical eliminativism about material objects. Drawing on doxographical evidence, particularly from Sextus Empiricus and Plutarch’s reports on the Epicurean Colotes, Zilioli argues that the Cyrenaics, beyond endorsing a “mild” indeterminacy thesis that denies determinate secondary qualities to things, also appear committed to a stronger thesis rejecting the existence of numerically distinct, self-identical material objects. According to Zilioli, some textual evidence appears to support the claim that, in the Cyrenaic outlook, “we are confronted with an undifferentiated lump of matter, fully devoid of discrete items” (p. 92), which affects us in various ways. From this perspective, Zilioli offers an intriguing interpretation of Cyrenaic neologisms. The Cyrenaics, for instance, are reported to say: “I am horsed” instead of “I perceive a horse.” Zilioli argues that this linguistic choice reflects their radical notion of metaphysical indeterminacy, as it strips language of reference to objects, replacing it with descriptions of the qualitative affective changes the perceiver undergoes. In Chapter 6, Zilioli introduces a previously neglected discussion in ancient philosophy scholarship: solipsism. The Cyrenaics serve as a natural starting point, as their epistemological subjectivism, combined with their eliminativism about material objects, implies a radical solipsism—where individuals are confined to their private world of affections, with no access to a shared, public reality. However, Zilioli highlights a passage from Sextus (i.e. M. 7. 195-198) that challenges the image of the Cyrenaic individual as a radical solipsist. In this passage, (quoted in p. 109-10), Sextus says that, for the Cyrenaics, although “no criterion is common to human beings, common names are assigned to objects.” Humans describe things as sweet with a common language, despite lacking a shared experience of sweetness. That is, the Cyrenaic individual is not equipped with a private language to name her own private affections. Zilioli argues that if Sextus’ report is accurate, the Cyrenaic recognition of the need for a public language to name private affections tempers the radical solipsistic portrayal of the Cyrenaics in other testimonies. To clarify this point, Zilioli invokes Wittgenstein’s argument on the impossibility of a private language for naming inner sensations, as it poses a strong challenge to solipsism. With some further references to Wittgenstein, Zilioli ultimately concludes that there must be a “residual” sort of solipsism to the Cyrenaic outlook, insofar as they consistently insist on the infallibility of an unalienable inner world of private affections.
The philosophical energy of the book does not decelerate in the Conclusion one bit. Here Zilioli offers a synoptic overview of the book’s main argument while demonstrating how a comparative reading of Greek and classical Buddhist philosophies exposes metaphysical indeterminacy as a heuristic framework that reveals eliminativist and nihilist tendencies and their mutual transitivity.
Ugo Zilioli’s book is rich in philosophical thought and argumentation and serves as a rare example—especially in classics—of writing the history of philosophy philosophically. Researchers and students of ancient Greek philosophy are its natural audience, but it also holds an obviously strong appeal for those interested in Buddhist philosophy and comparative studies in philosophy. For future editions, adding further elaboration in the Introduction on the book’s methodology could help readers better appreciate how its comparative approach contributes to the philosophical reconstruction of the arguments it examines.
I am confident that Zilioli’s Eliminativism will be a landmark in ancient Greek philosophy scholarship, bringing metaphysical indeterminacy to the forefront as a central issue in ancient metaphysics, diligently and persistently explored by a broad range of schools and thinkers in the Greek antiquity. I also strongly believe that much remains to be learned about ancient Greek philosophy by drawing on indeterminacy studies in contemporary analytic philosophy to build upon and extend Zilioli’s findings in this book.
I noticed some typos and other errors in the text, none of which affect its clarity. Instead of using my space to list them here, I will bring them to the attention of the author and editors.
Disclaimer: The author and the reviewer are collaborating in planning a conference but have no prior relationship.
Bibliography
Bett, R. (2000). Pyrrho, His Antecedents, His Legacy. Oxford: Oxford University Press.
Buckles, C. (2016). “The Ontology of the Secret Doctrine in Plato’s Theaetetus”, Phronesis 61 (3): 243-59.
Zilioli, U. (2012). The Cyrenaics. Durham: Acumen; reprinted for Routledge 2014.