Final answer:
Aristotle's three common conceptions of the highest good are pleasure, power, and eudaimonia, with the latter being the ultimate highest good. He advocates for the cultivation of virtue as the means to achieve human flourishing or eudaimonia, which involves the perfection of reason and character.
Step-by-step explanation:
The three common conceptions of the highest good according to Aristotle include pleasure, power, and eudaimonia (happiness or flourishing). However, after considering these candidates, Aristotle concludes that the highest good is eudaimonia. He believes that humans can achieve eudaimonia by cultivating virtues, which are habits of character that guide us in making the right decisions to lead a fulfilling life. For Aristotle, the purpose of the human being is closely tied to the function and rational capacity, and thus human excellence is achieved through the development and perfection of reason in accordance with virtues.
Aristotle differs from Plato in that he focuses on the observable world rather than a transcendental world of forms. His ethical framework is built upon natural observation and practical wisdom, which forms the basis of his virtue ethics. Pursuing virtue, in Aristotle's view, is the means to the end that is human flourishing, which is the ultimate goal of every human action.