Can reason prescribe the ends human beings should seek in life, as well as the means to those ends? This has been a central question in the history of ethics, and it is also a central question in Ayn Rand's Objectivist ethics. This lecture explores Ayn Rand's view on this question, bringing out its distinctive and important features and contrasting it with some of the most influential historical views, including those of Aristotle and Hume.