Loyalty is faithfulness or a devotion to a person, country, group, or cause (Philosophers disagree as to what things one can be loyal to. Some, as explained in more detail below, argue that one can be loyal to a broad range of things, whilst others argue that it is only possible for loyalty to be to another person and that it is strictly interpersonal.)
There are many aspects to loyalty. John Kleinig, professor of Philosophy at City University of New York, observes that over the years the idea has been treated by creative writers from Aeschylus through John Galsworthy to Conrad, by psychologists, psychiatrists, sociologists, scholars of religion, political economists, scholars of business and marketing, and — most particularly — by political theorists, who deal with it in terms of loyalty oaths and patriotism. As a philosophical concept, loyalty was largely untreated by philosophers until the work of Josiah Royce, the "grand exception" in Kleinig's words. John Ladd, professor of Philosophy at Brown University writing in the Macmillan Encyclopaedia of Philosophy in 1967, observes that by that time the subject had received "scant attention in philosophical literature". This he attributed to "odious" associations that the subject had with nationalism, including the nationalism of Nazism, and with the metaphysics of idealism, which he characterized as "obsolete". He argued that such associations were, however, faulty, and that the notion of loyalty is "an essential ingredient in any civilized and humane system of morals". Kleinig observes that from the 1980s onwards, the subject gained attention, with philosophers variously relating it to (amongst other things) professional ethics, whistleblowing, friendship, and virtue theory.