Aristotle’s Natural Philosophy

The Role of Animals in Aristotle’s Natural Philosophy: Or Why I Was Unable to Understand Aristotle’s Zoology until I Read His Physics

This page was written by Carolyn Scearce

Page from the Kitāb al-Hayawān (Book of Animals) by Al-Jahiz. Ninth Century. Basra. Wikimedia Commons.

This is a story about perceptions.  The clearest way I know how to illustrate the point I want to make, is to interweave the narrative of my own changing perceptions of the purpose and meaning of Aristotle’s zoological work, into a larger historical narrative of the changing fortunes of Aristotle’s reputation as a natural historian and philosopher.  Two and a half years ago, while preparing for general exams, I read the History of Animals for the first time.  At the time, I didn’t get a lot out of the reading.  It just seemed like a jumble of facts about animals: some interesting, many difficult to understand, and others clearly spurious.  Last summer, I read Aristotle’s remaining zoological texts: Parts of Animals, Generation of Animals, Movement of Animals and Progression of Animals.  Though I read these works at a much more reflective pace, I found them puzzling due to intrusions of philosophy and psychology that did not fit in to my previous experiences of natural history.  At that point, instead of giving up on Aristotle, I moved on to De Anima and Parva Naturalia.  Still confused, I started working my way through Aristotle’s natural philosophy, first reading On Generation and Corruption, then On the Heavens.  It was only when I came to Physics that I really started to understand the purpose of Aristotle’s zoological work.  By then, since I had already read the other zoological and natural philosophical texts, I read Meteorology and finally discovered why I had been so confused in the first place.

I came to Aristotle’s zoology, with the misconception that it was separate from his natural philosophy.  But in the first pages of Meteorology I discovered that Aristotle had developed a program for the study of nature that was meant to be approached in a clearly defined order.  Aristotle lays out this program: starting with the study of the “first causes of nature and with all natural motion” as covered in Physics, then moving to “the ordered movements of the stars in the heavens” as revealed in first two books of On the Heavens, continuing with “the number, kinds and mutual transformations of the four elements, and growth and decay in general” discussed in On the Heavens books three and four and in On Generation and Corruption, it then moves on to Meteorology and Aristotle ends his program with works on zoology and botany.  In my difficult encounter with Aristotle, I learned two important lessons: first that Aristotle’s zoology is part of his larger program of natural philosophy, and secondly just how disorienting reading a work out of context can be.

Now that I have provided an account of my own encounter with Aristotle’s zoology, I’ll briefly discuss how Aristotle’s zoology fits within the framework of his natural philosophy and then point out how some aspects of the transmission and reading patterns of Aristotle’s texts that have contributed to decontextualized readings of his zoology.

The driving theme in Aristotle’s natural philosophy is change.  Change is encountered in four forms.  These include the process of generation and corruption as well as the three forms of motion: quantitative, qualitative, and movement of place.  Quantitative motion is expressed through the increase or decrease of a substance, qualitative motion through alteration, and movement of place regards changes in location.  Starting with Physics, Aristotle indicates that the appropriate means of studying nature proceeds from first principles and from the study of generalities to that of particulars.  Aristotle’s tools for investigating nature are largely linguistic and logical in character, and he uses the same tools in his discussions of inanimate and animate forms of matter.

Aristotle maintains the theme of change throughout his zoological works.  It is, in fact, the organizing principle that structures his whole discussion of animals.  We can see this easily in four of the five main zoological works.  Parts of Animals investigates the bodily components that endow organisms with the capacity of movement and reproduction.  Movement of Animals and Progression of Animals further investigates the animal capacity for locomotion.  Generation of Animals discusses reproduction and development of animals, thereby covering the subjects of generation, as well as qualitative and quantitative motion.  In these works the reader also encounters the problem of what separates a lifeless body from one that is living.  Aristotle’s answer to the question is a soul.  The vegetative soul endows an organism, be it plant or animal, with the capacity for reproduction as well as growth and development.  The sensitive soul confers with it the capacity for sense perception, and is necessary for an animal to be aware of its environment in order to move within it.  And finally, the rational soul endows humans with the capacity for reason.  Since the soul is a necessary component of an organism’s capacity for change, De Anima can also be seen as a part of Aristotle’s larger discussion of natural philosophy.  The Parva Naturalia is harder to characterize since it is a collection of short works, but generally speaking there are clear thematic resonances related to change that can be found in the discussions on sensory perception, respiration, death, and sleep.  This only leaves us with History of Animals, which has frequently been read as an entirely unphilosophical work.  Ultimately, I will suggest that even this text can be read within the scheme of Aristotle’s natural philosophy, but in order to make this argument it helps to provide some context for the reading history of the zoological works, so I will save this explanation for the end.

The history of the transmission of Aristotle’s text has been one of irregular availability.  Even in antiquity Aristotle’s writings were not always widely circulated, and then only a handful of authors such as Theophrastus, Pliny and Galen demonstrated extensive knowledge of Aristotle’s zoological work.  The next appearance of the zoology is in the form of a ninth century Arabic translation.  Here we are talking about the De Animalibus which typically includes the three main zoological texts:  History of Animals, Parts of Animals, and Generation of Animals, and sometimes also includes Movement of Animals and Progression of Animals.   Ibn-Sina wrote a commentary on De Animalibus in the tenth century and Ibn Rushd in the twelfth century.

In the Middle Ages the natural philosophical texts: Physics, On the Heavens, On Generation and Corruption, and Meteorology were translated into Latin by Gerard of Cremona in the twelfth century.[1]

Beginning of a 13th-century Latin manuscript of Aristotle’s On Generation (De generatione). Ink and pigments on vellum, 1265. British Library Harley MS 3487, fol. 121v. From British Library item description: Oxford, where this manuscript was probably made, was a leading centre for the study of Aristotle. All students had to read set texts of Aristotle’s treatises with commentary, of which this book is an example. It is exceptional, though, because it is quite richly decorated with unusual images. Furthermore, it belonged to Nicholas of Cusa, a German theologian and cardinal, in the 15th century. The third book is called ‘On Coming Into Being and Passing Away’ (‘De Generatione et Corruptione’) and concerns chemical transformations and conditions of existence. In this manuscript, its first letter bears a picture showing a couple in bed and a nursemaid looking over an infant in a cradle nearby. Over the couple’s bed, a window, its curtains billowing inward, is open to the night sky. This image may have been modelled upon one in a secular book or possibly another scientific book, since the heavens were believed to influence humans at their conception and birth. The actual text by Aristotle is in the centre of the page, in larger writing. Surrounding it are the commentaries, much needed by the student who was expected to study Aristotle’s notoriously difficult writing.
De Anima and the Parva Naturalia also circulated in twelfth century.  However, De Animalibus did not make an appearance until the thirteenth century, when a few scholars including Albert the Great, Peter of Spain, and Gerard de Breuil wrote commentaries on the text.  Overall, with the exception of De Anima, Aristotle’s zoological texts received very little attention in the Middle Ages compared to those works that examined the motion and change of inanimate objects.

De Animalibus remained comparatively inaccessible until the 1476 publication of a Latin translation by Theodore of Gaza.[2]  In response to the increased availability of the text, humanist scholars in the early sixteenth century contributed new commentaries on Aristotle’s zoological work, sometimes emulating aspects of Aristotelian observation and animal dissections.

By the seventeenth century, the fortunes of Aristotelian natural philosophy declined due to rising anti-scholastic sentiment.  Francis Bacon, in particular, not only criticized Aristotle’s natural philosophy for premature generalization, and also forcefully criticized Aristotle’s methods of investigating natural history.[3]  It was only in the early nineteenth century that Aristotle’s zoological works attracted renewed interest, when naturalists such as Étienne Geoffroy Saint-Hilaire and Georges Cuvier pointed out the astute quality of some of Aristotle’s observations.  Over the course of the nineteenth century, Aristotle’s reputation as a zoologist recovered significantly.

In his lecture series on the history of the natural sciences, Cuvier identified Aristotle as the first comparative anatomist.  He held History of Animals up as the pinnacle of Aristotle’s achievement stating, “The other works of this great philosopher on natural history are much less correct, and very much less clear.”  Cuvier’s choice of History of Animal as exemplar is interesting, since prior readers of Aristotle’s zoology had difficulty classifying this text.  It was frequently read as an encyclopedic work, but as such it drew criticism for being extremely poorly organized.  For instance, in 1563 the Italian medical professor Cesare Odoni published a reinterpretation of this work.  In the dedication Odoni states: “Aristotle’s booklet on the History of Animals was until now so disorganized that it was hardly possible to grasp the entire ‘history’ of each animal.”[4]  In order to rectify Aristotle’s short comings, Odoni disassembled the text, recreating it as an alphabetized description of each animal.

I contend that History of Animals is neither a badly organized encyclopedia, or even at heart a work of comparative anatomy, but an integral component of Aristotle’s system of natural philosophy.  This work is often read as strictly natural history, but this reading can only be sustained if the work is read out of context of Aristotle’s other zoological and natural philosophical texts.  When I reread History of Animals in the light of Aristotle’s systems of inanimate and animate natural philosophy a clear organization emerged from the apparent chaos.  What became clear on the second reading was how similar in structure Aristotle’s collected facts about animals resembled the structure found in Parts of Animals and Generation of Animals.  If this is natural history, then it is natural history in the service of natural philosophy.

My reading of Aristotle has given me a lot to think about regarding how inaccurate preconceptions of texts can lead to misinterpretations.  Before my encounter with Aristotle’s works, I had spent a considerable portion of the two previous years acquainting myself with the history of natural history and had read a number general surveys of the early history of science.  None of these works prepared me to understand the deep thematic connections that tie Aristotle’s zoology to his natural philosophy.  It was only after I had started to recognize these connections for myself that I was able to identify modern historians of science who addressed the ties between Aristotle’s zoology and philosophy such James Lennox, or who directly point out animal motion within the context of his natural philosophy such as Edward Grant.[5]  To some degree there is a failure in the general literature on Aristotle to point out these connections.  But I think this failure relates strongly to historic reading patterns of Aristotle’s works rather than merely bad historiography.

Most of the work to assimilate Aristotle’s natural philosophy occurred centuries before naturalists attempted to come to grips with his zoology.  Over the course of history, there are substantive temporal and social divisions between the communities who read Aristotle’s inanimate and animate natural philosophies.  By the nineteenth century when natural historians exhibited interest in Aristotle’s zoological texts, possible associations between Aristotle’s zoology and natural philosophy constituted a liability rather than an advantage, since persistent “Baconian” rhetoric still disparaged Scholastic natural philosophy.

First page of printed edition of Albert the Great’s Commentary on Aristotle’s De Animalibus (1519). Image courtesy of the History of Science Collections, University of Oklahoma Libraries.

My own reading of Aristotle has sensitized me to the understanding, how easy it can be to misunderstand or ignore connections between the zoological and natural philosophical works, if they are read in isolation of each other or even out of order.  In the end, this painful ordeal of discovering the connections between Aristotle’s zoology and natural philosophy for myself allowed me to recognize the relationship much more clearly than if I had known of it from the beginning. I cannot say I regret the experience, because some lessons are best learned the hard way.


[1]   Edward Grant, A History of Natural Philosophy from the Ancient World to the Nineteenth Century, (New York: Cambridge University Press, 2007), 132.

[2]   Stefano Perfetti, Aristotle’s Zoology and Its Renaissance Commentators (1521-1601), (Leuven: Leuven University Press, 2000), v & 13-14.

[3] Lorraine Daston, “Baconian Facts, Academic Civility, and the Prehistory of Objectivity,” Annals of scholarship. Vol. 8 (1991), 344-345.

[4]   Perfetti, Aristotle’s Zoology, 189.

[5]    James Lennox, Aristotle’s Philosophy of Biology: Studies in the Origin of Biology. (Cambridge: Cambridge University Press, 2001).  For more references see the following statement from Armand Marie Leroi, The Lagoon: How Aristotle Invented Science, (New York: Penguin Books, 2014), 9. “In the twentieth century, a generation of great scholars began to examine Aristotle’s biological works not as natural history but as natural philosophy.  David Balme (London), Allan Gotthelf (New Jersey), Wolfgang Kullmann (Freiburg), James Lennox (Pittsburgh), Geoffrey Lloyd (Cambridge) and Pierre Pellegrin (Paris) gave as a new, thrilling Aristotle.”

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