Find out according to whom, there are four classes of absolute duties, viz. duties to self, duty to indeterminate person, duty to the sovereign and duty to one who is not a human being.

Austin says that a "relative duty" corresponds to a right. It is a duty to be fulfilled towards a determinate person; while on the other side, there are duties to which there are no corresponding rights. He named such duties as "absolute duties" and he said that there are four kinds of such absolute duties, viz. (i)    Self-regarding duties (ii)   Duties owed to persons indefinitely (iii)  Duties not regarding persons, i.e. the duties owed to God and lower animals (iv)  Duties owed to the sovereign