I'm starting to see that Aristotle's conception of ἀρετή (which I translate as thriving but which is more commonly translated as excellence or virtue) describes a deliberate practice of good judgment, reasoned choice, and planned activity resulting in a balance between extremes of action and emotional reaction in a particular domain of human life.
Example: frugality or financial responsibility (not an ἀρετή that Aristotle discusses, by the way). Money troubles are one of the greatest sources of stress in modern times, so doing well in this domain is important to your happiness and success in life. Furthermore, let's say that in your later years you would like to pursue a more beautiful existence through philanthropic activities, devotion to a craft, or a life of inquiry - all of which require you to build up a financial cushion. To achieve your goals, you can't hope to win the lottery or get lucky with a hot investing scheme. Instead, you need to cultivate a deliberate practice of financial responsibility consisting of numerous activities that are based in clear perception, honesty with yourself, good judgment, and other mental thrivings. Such activities might include dedicating a large percentage of your salary to savings, paying your bills on time and in full, saving up for large expenditures, not incurring debt, thinking about the long-term impact of even small costs (like going out to lunch every day), budgeting for and understanding your expenses, investing reasonably without succumbing to fear and greed, etc. You won't learn such practices in philosophy class, but they are directly connected with living well because they help you face financial crises with equanimity, take care of yourself and your family, and engage in finer pursuits later in life.
Failings, too, are practices (say, prodigality or financial irresponsibility as an excess in this area - much more common than the deficiency of cheapness). There is judgment involved, but it's poor judgment. There is choice involved, but it's unreasoned choice. There is planning involved, but for misguided activities (e.g., trips to Las Vegas to shop and gamble). There is willful ignorance instead of constructive knowledge, self-deception instead of truthfulness, etc. All of this bespeaks a stunted humanity in one area of your life - which can bleed over into many other areas, or the whole of it.
Because philosophy is the love and practice of wisdom, a good and deliberate practice in any important domain of life (work, love, family, health, finance, friendship, thought, emotion, etc.) is a philosophical endeavor and an application of philosophical insight to a life well lived. This is the role of ἀρετή in human existence.
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