Nicomachean Ethics · Chapter
Chapter XIII: The Division of the Soul and the Foundation of Virtue explained
Aristotle argues that since happiness is an activity of the soul in accordance with perfect virtue, the statesman must study the soul to understand virtue.
What happens
Aristotle argues that since happiness is an activity of the soul in accordance with perfect virtue, the statesman must study the soul to understand virtue. He distinguishes between a rational and an irrational part of the soul, further dividing the irrational into a vegetative part (shared with plants, irrelevant to human excellence) and a desiring part that can listen to reason. This division grounds the distinction between intellectual virtues (e.g., wisdom, prudence) and moral virtues (e.g., liberality, temperance).
Themes in this chapter
Virtue and Character
The chapter introduces the distinction between intellectual and moral virtues, grounding character in the soul's rational and irrational parts.
Practical Wisdom and Reason
Aristotle discusses how the irrational part of the soul can listen to reason, laying the groundwork for practical wisdom and moral development.
Characters to notice
- Aristotle
Author of the text; presents the division of the soul and its relevance to virtue and politics.
Key passages
“Since happiness is an exercise of the vital faculties in accordance with perfect virtue or excellence, we will now inquire about virtue or excellence; for this will probably help us in our inquiry about happiness.”
Because happiness consists in actively using our faculties with complete virtue, we must first investigate virtue itself, as this will clarify our search for happiness.
Opening statement linking happiness to the study of virtue.
“Two parts of the soul are distinguished, an irrational and a rational part.”
The soul is divided into two main parts: one that lacks reason and one that possesses it.
Key division of the soul that underpins the classification of virtues.
“Of the irrational part, again, one division seems to be common to all things that live, and to be possessed by plants—I mean that which causes nutrition and growth.”
One part of the irrational soul is the vegetative faculty, shared with all living things including plants, responsible for nutrition and growth.
Identification of the nutritive principle as irrelevant to human virtue.
“But there seems to be another vital principle that is irrational, and yet in some way partakes of reason.”
There is another irrational element that nonetheless can share in reason, as seen in the continent and incontinent man.
Introduction of the desiring part that can obey reason, crucial for moral virtue.
“Now, on this division of the faculties is based the division of excellence; for we speak of intellectual excellences and of moral excellences; wisdom and understanding and prudence we call intellectual, liberality and temperance we call moral virtues or excellences.”
The distinction between the rational and the obedient irrational parts leads to two kinds of excellence: intellectual virtues like wisdom and prudence, and moral virtues like liberality and temperance.
Final classification of virtues based on the soul's structure.