Rational Soul: Humans. Accounts for same things as nutritive and sensitive souls as well as rationality.
Every object (animate or inanimate) has a function. The function of a living organism is determined by its soul; specifically, its purpose is to live according to the highest capacities of its soul. Thus, the function of a human being is to live according to reason. A virtue is any characteristic that helps one fulfill this function. The Greek term “arête” means “excellence.” It is often used to refer to virtues.
The Structure of Virtues:
Each virtue is a balance between having too much of something and having too little of that something. E.g., The virtue of moderation is the balance between indulging between too little pleasure and indulging in too much pleasure.
Each virtue is a balance point between two vices: the vice of deficiency and the vice of excess.
The balance point for each virtue varies from person to person. Finding the balance point (virtue) requires using reason, the highest capacity of the soul.
In addition to finding the proper balance point, one must learn to be comfortable with that level of the characteristic.