Tools may be animate as well as inanimate; for instance, a ship's captain uses a lifeless rudder, but a living man for watch; for a servant is, from the point of view of his craft, categorized as one of its tools. So any piece of property can be regarded as a tool enabling a man to live, and his property is an assemblage of such tools; a slave is a sort of living piece of property; and like any other servant is a tool in charge of other tools.

The law is reason, free from passion.

The happy life is regarded as a life in conformity with virtue. It is a life which involves effort and is not spent in amusement.

Democracy is when the indigent, and not the men of property, are the rulers.

We ought, so far as it lies within our power, to aspire to immortality, and do all that we can to live in conformity with the highest that is within us; for even if it is small in quantity, in power and preciousness, it far excels all the rest.

The body is at its best between the ages of thirty and thirty-five.

Some men are just as sure of the truth of their opinions as are others of what they know.