Virtue ethics focuses on the nature of the agent, duty ethics (deontology) focus on the nature of the action, while consequentialism focuses on the nature of the outcome. In a very real sense, all major ethical discussions can be transformed between these three perspectives, although there are some boundary cases which are better dealt by the specific spins. For instance, Phillipa Foot's Trolley Problem shows that we cannot escape consequentialism in all instances since there are some ethical situations which can only be judged in terms of outcomes. But this does not mean that consequentialism has any prior status to validity, especially given the transformability of one system into another.
All three approaches have long histories. The agent-focussed approach is the oldest, dating back to Aristotle and Plato in the West and to Confucius and Buddha in the East. The action-focussed approach found its full flowering in the work of Immanuel Kant, the 18th century Prussian who many consider the greatest philosopher who ever lived; from the train of thought that Kant put in motion emerges modern moral concepts such as freedom and Human Rights. Finally, the outcome-focussed approach finds it roots in the writing of Machiavelli (who reported on the pragmatic requirements of leadership in the 16th century) and flowered in the utilitarian ideas of Jeremy Bentham and John Stewart Mills. While today the panoply of specific ethical systems is dizzying, by necessity they all represent variations on these three basic themes.
Part 13 of 23 in the Pentenary series.