Aristotle’s works on politics, ethics, and metaphysics have made him one of the most widely read of the Greek philosophers. The title of this book, On the Soul, is a signal to the reader that the topic is critical to understanding humans. Some scholars believe On the Soul was part of Aristotle’s general lectures on biology at his institution of learning, the Lyceum, while others place the work at a later point in his life. Aristotle typically wrote and then revised many of his works, and this book likely was revised several times as well.
On the Soul is divided into three books with several chapters in each. Book 1 begins with Aristotle’s assertion of the importance of his topic. Understanding the nature of the soul, he claims, is important to understanding the principle that animates all animal life. He is quick to acknowledge that the topic is a difficult one; but its importance is obvious. Equally important, he argues, is how one approaches the topic of understanding the essence of the soul, its form or true nature. Accounting for the properties that make up that essence can lead a person to understand the soul itself.
The balance of book 1 is taken up with Aristotle’s effort to obtain an understanding of these properties through the works of other philosophers. While he advances his reasons for disagreeing with their wisdom, Aristotle concludes from his survey of their thinking that all are in agreement that the soul is in some way joined to the body and is therefore the origin of movement. He rejects this conclusion for several reasons, however, not the least because it would mean the soul would have to have a location or place in the body, a conclusion he doubts. In other words, Aristotle makes it clear from the beginning of On the Soul that he believes the essence of the soul is not a material thing.
Aristotle ends book 1 by arguing against what he considers the implausible belief that the soul is created through parts of the body or a mixture of parts of the body, corresponding to the elements of fire, water, and air (earth, he acknowledges, has no advocates on this point). Instead, he argues, the soul is unified in its essence.
After disposing of the thoughts of others on the soul, Aristotle sets out in book 2 to make a fresh start on his subject. He proposes to study the nature of the soul in all living things, arguing that the soul is the source of all movement and the essence of life. From this, he goes on to examine life in terms of growth, finding that all living things possess a nutritive soul that urges them to feed themselves and to reproduce. In this sense, he concludes, all living things, both plant and animal, are animated by this type of soul.
(The entire section is 1136 words.)