Miira Tuominen’s volume investigates the application of the principle of justice in Porphyry’s treatise On Abstinence. In particular, the study examines the ethical implications of using living beings both as food and as sources of other material products. In Chapter 1, which serves as an introduction, Tuominen explains that although Porphyry’s work has often been interpreted by scholars as a defence of vegetarianism, she intends to demonstrate that its ethical concerns extend well beyond this single issue. She focuses on the argument developed in On Abstinence that justice towards living beings must hold a central place within a philosophical life (p. 12). Porphyry’s treatise, she argues, offers an account of what is required by justice in order to attain the highest degree of divinity. According to Tuominen, Porphyry holds the view that justice demands abstaining from causing harm—namely, inflicting pain or taking life—upon living beings. A fundamental principle in Porphyry’s thought is assimilation to God, understood as a means of escaping the evils associated with an embodied existence. Tuominen thus aims to explore how Porphyry conceived the attainment of the good—namely, through inner moderation, justice, purity or theoretical contemplation, and truth. A further focal point of her discussion is the moral status of animals.
Following this introductory chapter, Tuominen develops her study over six further chapters, in addition to a final one outlining her overall conclusions.
Chapter 2 addresses Book I of On Abstinence. Here Porphyry proposes the firm pursuit of assimilation to God as the ideal way of life for philosophers. Achieving this condition requires transforming one’s life by changing not only one’s beliefs but also one’s actions, which entails abstaining from the consumption of meat. Purification begins with the body and culminates in what lies within it—the inner human being. Tuominen emphasises that, in Porphyry’s view, the best form of life is attained through a meat-free diet, and she notes that similar positions can also be found among Stoic and Epicurean thinkers.
Chapter 3 deals with Book II of On Abstinence. According to Tuominen, here Porphyry argues that assimilation to God requires both piety and justice, yet piety excludes the sacrifice of animals. Porphyry also emphasises the role of purity in his discussion of philosophical piety. Philosophers must refrain from eating animal flesh if they are to remain pure, and such inner purity serves to detach them from their bodily dimension.
Chapter 4 focuses on Book III of On Abstinence, where Porphyry confronts the challenge presented by his opponents, who maintain that animals do not lie within the remit of justice. Tuominen shows how Porphyry argues that his adversaries fail to successfully defend their argument, be it on the grounds of animals’ alleged lack of rationality and incapacity to enter into agreements, or on the basis of the general dissimilarity between human beings and other living beings. Concerning animal rationality, Porphyry maintains that animals should be regarded as possessing preconceptions—that is, seeds for the development of reason. Their capacity to distinguish what is beneficial from what is harmful differs only marginally from human rationality.
In Chapter 5, Tuominen continues her analysis of Book III, concentrating in particular on the passages at 3.26–27. Here Porphyry argues that the right to defend oneself against dangerous or harmful animals does not justify the killing, mistreatment, or consumption of domesticated ones. Since justice consists in refraining from causing harm, it must be extended to all harmless living creatures. Justice, when defined in this way, should be attributed to actions rather than to the inner disposition of the soul. Porphyry further contends that killing animals for food is unjust. He emphasises that the desire for pleasure is the principal motivation behind unjust actions, and that the soul must be entirely free from such impulses. According to Tuominen, Porphyry places particular emphasis on extending justice in practice, so as to avoid harming not only animals but also plants.
Chapter 6 examines Book IV of On Abstinence. Here Porphyry presents, as it were, a series of ‘case studies’ drawn from the lifestyles of various groups or communities who practice abstinence from meat. The examples he discusses include the ancient Greeks, Spartans, Egyptian priests, Essenes, Syrians, Magi, Brahmans, and Samaneans. Porphyry maintains that philosophers must impose upon themselves a moral code of abstinence. In Book IV he gathers testimonies concerning dietary (and other) restrictions among different peoples and cultures, particularly among their wise men, such as priests or monks. These testimonies concerning abstinent priest-sages or philosophers reinforce the connection between abstinence, on the one hand, and wisdom and assimilation to God, on the other. Wisdom underpins abstinence. For Porphyry, asceticism constitutes a further good, adding to personal purity and detachment from bodily concerns, and enhancing one’s capacity to act justly towards others. Every injustice, he maintains, originates in an inner state dominated by desire.
In Chapter 7, Tuominen draws a set of general conclusions regarding On Abstinence. First, she offers a synthesis of her analysis, emphasising that the ideal advocated by Porphyry is assimilation to God, grounded in piety, justice, and wisdom. Then, she underlines that Porphyry advances a conception of justice in action as abstention from harming animate beings, and that he displays genuine moral concern for such beings. The extension of justice, in Porphyry’s view, must go beyond humanity to include animals and even plants. Justice in outward actions presupposes order, purity, and the soul’s theoretical virtue. Moreover, Tuominen offers an original interpretation, identifying a more practical and polemical dimension in Porphyry’s approach than is typically associated with late antique Platonist ethical discussions. She argues that Porphyry’s position offers fruitful insights for contemporary debates in animal and environmental ethics. Porphyry appears close to the view that life possesses intrinsic value, even though he explicitly acknowledges that self-defence and the limitation of harmful populations are justified. Finally, Tuominen concludes that the notion of intrinsic goods (and evils) best captures the orientation of Porphyry’s treatise. The intrinsic goods of animals and plants include their life, their physical integrity, and the integrity of their products, such as milk and fruits. In Tuominen’s interpretation, Porphyry anticipates the modern concept of integrity—the idea that living beings possess a wholeness or unity whose violation constitutes injustice. His thought firmly opposes the injustice of taking the life of innocent creatures.
Taken as a whole, Tuominen’s volume offers a careful philosophical analysis that highlights the innovative elements of a treatise long regarded primarily as an expression of late Platonism. She rightly reiterates Porphyry’s moral concern and underscores the originality and enduring relevance of his idea that the highest expression of justice in outward action consists in refraining from harming others.