The human faculties of perception, judgment, discriminative feeling, mental activity, and even moral preference, are exercised only in making a choice. He who does anything because it is the custom, makes no choice. He gains no practice either in discerning or in desiring what is best. The mental and moral, like the muscular powers, are improved only by being used. The faculties are called into no exercise by doing a thing merely because others do it, no more than by believing a thing only because others believe it. (from "On Liberty: On Individuality, as One of the Elements of Wellbeing"; chapter 3, section 3) Explain Mill's argument in this passage and describe, in your own words, how this excerpt applies to public and private life today. Your answer should be at least one hundred words.