Teleological Theories

Classical ethical theories can be categorized in two major divisions, the first being teleological. These theories measure the worth of an action by its results: The best action produces the greatest good for the most people. The emphasis is on determining what is good, rather than what is right (Ward, 1998). Consequently, it is possible to select a course of action which is harmful or unjust to an individual or group, as long as the benefits to others outweigh these negative effects. As long as the action produces more good than harm, it is ethically correct, according to teleological theory.
Evaluating an action based solely on its results creates difficulty, in that it is troublesome – often impossible – to ascertain all of the many consequences. The complexities of an issue due to such considerations as the interrelationships between people and systems and uncertainties in the many variables make it problematic to predict accurately the consequences of an action. Thus, teleological theories are limited in their usefulness for guiding a person through an ethical dilemma.
Furthermore, adherents of these theories do not seek to evaluate the process used to reach a goal or outcome. The common philosophical question of "Do the ends justify the means?" is not an issue in teleological theories because the means are irrelevant. Since the results are the only measure of the value of an action, any methods, no matter how questionable, can be justified to achieve any desirable objective.

(Source: http://zyx.org/Teleological.htm)