Can an action that is required of one be referred to as obligation or duty? If Saeed ought to ‘X’ does not imply being already has a motive to ‘X’? i.e can he coherently say, ‘I acknowledge that I ought to X, but that gives me no motive to ‘X’? Would this count as genuine acknowledge? And can it be true that one ought to X, if one think one ought but remains completely unmoved? Also is it the case that we ought to cat from certain motives?
The basis of many obligations is a contract, which need be only implicit, if implicit contracts are possible. There may be many reasons why I ought to obey the law, but I only have an obligation to obey if I have incurred that obligation perhaps on some form of perspectives. Obligations are primarily moral or legal. They are also to some moral agent (corporations, persons, etc). If I buy a dog, no doubt I ought to feed him, but any obligation I am under must be to the seller, or perhaps to society.
Being obliged is wider than being under obligation. Whatever matters now is the lack of alternatives, not the element of incurring. The alternatives excluded may be physically or prudentially rather than morally or legally impossible (I was obliged, but not under obligation to buy car). Also one need not, though one may be obliged to someone. But one cannot be obliged to do what is not morally at least excusable: a soldier is not obliged to flee the battle, no matter how prudent that may be.
Obligatory belongs roughly with ‘obligation’. It is not confined to the moral and legal (there can be obligatory moves in a game), but it presupposes riles and does not cover cases of being physically or prudentially obliged.
Duty is primarily connected with roles, whether or not these are voluntarily undertaken. One has duties as a leader, secretary, father etc. Duties tend to be of longer standing and less ad-hoc than obligation: one meets one’s obligations as one incurs them, but doe one’s duty or discharges one’s duties in the normal course of things.
Duties and obligation are therefore special kinds of things we morally or legally ought to do, through it does not follow that we always ought to perform them, since they may be overridden, whether by other duties, etc, or even by something non-moral. Another question introduces rights. Must there be a correlative right wherever there is a duty or obligation, and vice versa? Do animals have right, and do we have duties to them?