For nature by the same cause, provided it remain in the same condition, always produces the same effect, so that either coming-to-be or passing-away will always result.
Anybody can become angry - that is easy, but to be angry with the right person and to the right degree and at the right time and for the right purpose, and in the right way - that is not within everybody's power and is not easy.
Some vices miss what is right because they are deficient, others because they are excessive, in feelings or in actions, while virtue finds and chooses the mean.
There is an ideal of excellence for any particular craft or occupation; similarly there must be an excellent that we can achieve as human beings. That is, we can live our lives as a whole in such a way that they can be judged not just as excellent in this respect or in that occupation, but as excellent, period. Only when we develop our truly human capacities sufficiently to achieve this human excellent will we have lives blessed with happiness.
And of course, the brain is not responsible for any of the sensations at all. The correct view is that the seat and source of sensation is the region of the heart.
... the good for man is an activity of the soul in accordance with virtue, or if there are more kinds of virtue than one, in accordance with the best and most perfect kind.
The good lawgiver should inquire how states and races of men and communities may participate in a good life, and in the happiness which is attainable by them.