Students of philosophy usually begin their study of Aristotle with his ethical writings, and then make their way to his metaphysics and epistemology. Eventually serious students of Aristotle must hunker down and work through the biological writings. For only by seeing how Aristotle appeals to form in his account of particular kinds of living things can one appreciate what form is, for him. Only by seeing how Aristotle accounts for the anatomy and behavior of the living things around him can one appreciate Aristotle’s thoughts on what an explanation is the methods by which one arrives at them. And only by closely studying Aristotle’s appeal to the good and the divine in his biological writings can one fully appreciate his thoughts on what is the good life for us, and how he takes divine principles to be at work throughout the cosmos.
But the biological writings can be a difficult slog. Page after page presents the reader with details concerning the digestive tracts of selachia and sanguineous animals. Many animal kinds are unfamiliar, and it is hard for the one who is not a biologist to keep straight on the details concerning their squishy brown internal organs. Causal explanations are offered on apparently arbitrary grounds. Compared to the biological writings, dry texts like the Topics and Rhetoric seem like page-turners.
Things are easier now. In recent decades Aristotle’s biological writings have been extensively studied by historians of philosophy and science, most notably David Balme, Alan Gotthelf, and James Lennox. They have helped to make sense of the aim and structure of the biological writings, showing how they allow us to more fully appreciate the metaphysical and epistemological views presented in texts like Metaphysics and Posterior Analytics. This research has given philosophers of science a lens by which readers of the biological writings can focus in on matters of enduring philosophical interest. Nonetheless, for most of us the biological details presented by the texts are still material to be endured. We students of philosophy eagerly begin with the lofty and abstruse, and move begrudgingly to detailed descriptions of squirming squiggly things.
As a biologist, Armand Leroi took the opposite path into the study of Aristotle. Wandering through an Athens bookstore, he stumbled upon a set of the old Oxford English translations of Aristotle. He shared the prejudice of many scientists that Aristotle was hopelessly obscurantist who set back the dawn of science for centuries, but, letting curiosity get the better of him, Leroi opened a biological text at random. His eye was caught by page after page of detailed description of the creatures he had studied, and had come to know and love. Leroi immediately recognized the accuracy of Aristotle’s observational eye, and the good sense that lay behind many of Aristotle’s causal explanations. He recognized in Aristotle a fellow scientist, and took on the study of Aristotle in order to more fully appreciate the scope and magnitude of Aristotle’s scientific achievement.
In quest of Aristotle the scientist, Leroi traveled to the island of Lesbos in the Aegean Sea, where Aristotle spent two years, with his friend and student Theophrastus by his side. Theophrastus concentrated on an exhaustive survey and study of flora; Aristotle concentrated on the fauna. Leroi joins Aristotle in exploring the same land and waters. He talks to the men who fish the same waters as those fished by the men with whom Aristotle spoke, gathering their lore as the “commonly accepted opinions” (endoxa) with which theoretical inquiry must begin.
The beautifully produced BBC film Aristotle’s Lagoon, which was the first result of Leroi’s quest to more fully understand Aristotle allows us to visit the land of Lesbos, and its waters teeming with life. Seeing Leroi lean over pier, picking at acquatic life, we can well imagine Aristotle doing the same. It is one thing to read Aristotle exhorting the study of biology by quoting Heraclitus' “There are gods here too” – it is another see him in Leroi, fascinated by the life form he explores. And it is one thing to read Aristotle’s descriptions of the morphology and anatomy of the cuttlefish, and it is another to see Leroi cutting the cuttlefish open as Aristotle would have, separated its organs, and show us clearly what Aristotle got right and what he got wrong.
A picture is worth a thousand words, and the film images of the geography of Lesbos and the animals Aristotle identified, with their eggs, embryos, and internal organs, are no substitute for the maps and drawings (based on the illustration in Renaissance editions) within The Lagoon, as fine as they are. But Leroi’s travel writing is lively evocative prose. And, though a “popular” book written for non-specialists, Leroi discusses the theoretical implications of Aristotle’s biology in a way not possible in a television documentary.
Leroi takes full advantage of the progress that historians of science and philosophy have made in understanding the nature of Aristotle’s project. In clear and engaging prose he lays out the basics in accurate yet nontechnical accounts, which allow the reader to have a basic sense of what Aristotle means by form, soul, and each of the four causes. Leroi clarifies how the notions of essence and definition play a crucial role in Aristotle’s explanatory scheme, but skirts the deeper issues of reference, cognition, modality, and ontology on which the philosophical literature on Aristotle has concentrated. As such Leroi’s book provides an ideal nontechnical introductory account of the Aristotelian world view.
The true contribution of the book lies elsewhere. As a professional biologist who has himself made the fauna of Lesbos an object of special study, Leroi gives us a selective tour of Aristotle descriptive and causal accounts. Leroi points out that Aristotle’s biological writings have not been read for their biological interest for centuries; he takes this to be a shame, since so many of Aristotle’s observations are perspicacious. A book like that of Leroi is for now our best guide as to what are these animal kinds that Aristotle discusses, and to what extent Aristotle’s account is accurate. (I dream of the day that someone produces a hyperlinked version of the texts, by which one can easily learn about the animal kinds Aristotle discusses, and see films of what he describes.) Leroi’s enthusiasm for his subject is contagious, and book like this infuses the texts with new interest.
Leroi’s main goal, however, is not to teach us about cuttlefish. It is to read Aristotle as teaching us what it is for a scientist to study a creature like the cuttlefish. Leroi indicates many respects in which Aristotle’s discusses follow contemporary biological practice. One begins with observations; and determines the statistical regularities that hold among observed features. (An appendix which offers he tables of the correlations detected in the biological writings is an especially interesting feature of the book.) On this basis one works up causal accounts explaining the correlations in question. The causal accounts can be generalized across the various animal kinds; as in a contemporary biological textbook, it is the processes, found across the kinds, that are objects of study. Once a process in general is understood, one studies how it is manifested in different kinds. All explanations are functional; an organ or activity is understood by determining the function that it plays in the life form as a whole. Further, function must take account not only of the way processes interact within a single organism, but of the way the organism interacts with other organisms, and features of its environment. Leroi’s Aristotle is a proto-ecologist.
All of this is enlightening. Leroi slips only in drawing too sharp a line between Aristotle the scientist and Aristotle the philosopher taken by abstruse speculations. The villain, on Leroi’s account, is Plato, whose Timaeus is based on little in the way of direct observation, and too much on fanciful speculation motivated by ethical and theological concerns. Leroi recognizes that Aristotle, too, appeals not only to functionality, but to the good (understood as something different from the fitting) and the divine. For Leroi these are unfortunate archaic excrescences on Aristotle’s properly scientific work. But this is not how Aristotle sees things.
Recent philosophy of science has called into question the possibility of scientific inquiry without presuppositions of one sort or another. Aristotle’s own presuppositions may have been replaced by others, but that is not to say that the process of collating facts and working towards explanatory principles, which Leroi so effectively shows is at work in both Aristotle and contemporary science, can be accomplished in the absence of a more encompassing account which isolates certain questions as important. Plato knew this, presenting his biology within the context of a mythical framework that was both grandly cosmogonical and relevant to the ethical and political concerns of his time. Aristotle knew it too, and took the ultimate motive power of living things, and their ultimate purpose, to be located in the divine. Leroi’s excision of these aspect of Aristotle’s thought, as largely irrelevant to his account of what science is, may tell us more about scientific thought and practice in the beginning of the 21st century, than it does about the thought and practice of Aristotle the scientist.
Owen Goldin is Professor of Philosophy at Marquette University in Milwaukee, Wisconsin and the author of Explaining an Eclipse: Aristotle's Posterior Analytics 2.1-10