Our virtues are voluntary (and in fact we are in a sense ourselves partly the cause of our moral dispositions, and it is our having a certain character that makes us set up an end of a certain kind), it follows that our vices are voluntary also; they are voluntary in the same manner as our virtues.
The vices respectively fall short of or exceed what is right in both passions and actions, while virtue both finds and chooses that which is intermediate.
Rhetoric is the counterpart of logic; since both are conversant with subjects of such a nature as it is the business of all to have a certain knowledge of, and which belong to no distinct science. Wherefore all men in some way participate of both; since all, to a certain extent, attempt, as well to sift, as to maintain an argument; as well to defend themselves, as to impeach.
At first he who invented any art that went beyond the common perceptions of man was naturally admired by men, not only because there was something useful in the inventions, but because he was thought wise and superior to the rest. But as more arts were invented, and some were directed to the necessities of life, others to its recreation, the inventors of the latter were always regarded as wiser than the inventors of the former, because their branches of knowledge did not aim at utility.
What is the highest of all goods achievable by action? ...both the general run of man and people of superior refinement say that it is happiness ...but with regard to what happiness is they differ.
Nature does nothing in vain. Therefore, it is imperative for persons to act in accordance with their nature and develop their latent talents, in order to be content and complete.