Aristotle's ethical writings, notably his Nicomachean Ethics, serve as the groundwork for one of three dominant schools of moral philosophy. This perspective is known as virtue ethics, while it's rivals are consequentialism (or utilitarianism) and deontology, respectively. Moral philosophers and practitioners of the Aristotelian approach to ethics believe in a naturalistic conception of human morality based on the acquisition and cultivation of virtues, functions, or capabilities. A virtue is a strength of character that contributes to an agents flourishing or happiness. These capabilities can be moral, as in the case of courage, or intellectual, as with practical reasoning. The moral weight of ethical claims are identified with the individual's virtuous activity, and not necessarily with the outcomes that obtain from such activity, or the potential obligations that might be imposed by socials norms, upbringing, or codes of conduct. Aristotle's insights in this area should not be underestimated. The fact that his thought is still viable after 2,000 years of Western history is a testament to his moral expertise.