text: In ethics, deontological ethics or deontology (Greek: Deon meaning obligation or duty) is a theory holding that decisions should be made solely or primarily by considering one's duties and the rights of others. Deontology posits the existence of a priori moral obligations, further suggesting that people ought to live by a set of defined principles that do not change merely as a result of a change in circumstances (ie. situational ethics).\n\nOne of the most important implications of deontology is that praiseworthy goals can never justify immoral actions, in contrast to doctrines that claim the ends justify the means. Deontology is directly in opposition to consequentialism, an ethical theory in which the ends can justify the means because decisions are judged primarily in terms of their consequences.