Opinion involves belief (for without belief in what we opine we cannot have an opinion), and in the brutes though we often find imagination we never find belief.
But if nothing but soul, or in soul mind, is qualified to count, it is impossible for there to be time unless there is soul, but only that of which time is an attribute, i.e. if change can exist without soul.
Happiness is something final and complete in itself, as being the aim and end of all practical activities whatever .... Happiness then we define as the active exercise of the mind in conformity with perfect goodness or virtue.
For contemplation is both the highest form of activity (since the intellect is the highest thing in us, and the objects that it apprehends are the highest things that can be known), and also it is the most continuous, because we are more capable of continuous contemplation than we are of any practical activity.
Not every action or emotion however admits of the observance of a due mean. Indeed the very names of some directly imply evil, for instance malice, shamelessness, envy, and, of actions, adultery, theft, murder. All these and similar actions and feelings are blamed as being bad in themselves; it is not the excess or deficiency of them that we blame. It is impossible therefore ever to go right in regard to them - one must always be wrong.
It is clear, then, that wisdom is knowledge having to do with certain principles and causes. But now, since it is this knowledge that we are seeking, we must consider the following point: of what kind of principles and of what kind of causes is wisdom the knowledge?