Part I History of Ethics
Life of Socrates
Part II Concepts and Problems
Normative Ethics and Applied Ethics
Part III Applied Ethics
Field of Applied Ethics
Acting from Duty
Deontological normative ethical theories place the locus of right and wrong in autonomous adherence to moral laws or duties.
Monistic deontology -- Kant's Categorical Imperative ("Act only on that maxim whereby thou canst at the same time will that it should become a universal law") provides the source of right action. Its first formulation states "Act as if the maxim of your action were to secure through your will a universal law of nature;" its second formulation states "Always act so as to treat humanity, whether in your own person or that of another, as an end in itself, never as a means only." Actions that conform to these imperatives (i.e., right actions) and are, furthermore, done from a sense of duty, are the epitome of morally praiseworthy actions.
Critics of Kant's approach claim that his Categorical Imperative does not contain within it a way to resolve conflicts of duties. "Lying is wrong" can be interpreted as "Never lie" and thus Universal Principles can 'harden' into Absolute Principles.
Pluralistic deontology -- For the 20th Century philosopher W. D. Ross, there are a number of duties that reflection reveals -- and these form a group of prima facie obligations. The phrase "prima facie" ('all things being equal') refers to the fact that these duties do not bind us absolutely, but rather that they generally hold -- absent any further considerations. Two key duties are nonmaleficence (don't harm others) and beneficence (help others). Other prima facie duties include 'don't lie,' 'don't kill,' keep promises,' etc.
When conflicts occur between duties, our actual duty becomes that which "intuitive judgment" discerns as the right thing to do (e.g., lying to save the life of an innocent person). Critics are cautious about referring to 'intuition' as the criterion for determining our actual course of action. Stephen Toulmin (Reason in Ethics, 1950) suggested that we "weigh up, as well as we can, the risks involved in ignoring either, and choose 'the lesser of two evils'." Thus, while the principles may be deontic in nature, a resolution of conflicts of principles could appeal to probable consequences.
See excerpts from the Routledge Encyclopedia of Philosophy article on "Universalism."