Summum bonum is an expression used in medieval philosophy to describe the ultimate importance, the singular and most ultimate end which human beings are to pursue. The summum bonum is generally thought of as being an end in itself, and at the same time containing all other good. In Hinduism and other Eastern Religions, Summum bonum is cognate with such concepts as Dharma, Tao, Shreyas, Moksha, Liberation, Jeevan Mukti, and Self Realization.
The concept, as well as the philosophical and theological consequences drawn from the purported existence of a more or less clearly defined summum bonum, could be traced back to the earliest forms of monotheism. In the Western world, the concept was introduced by the neoplatonic philosophers, and described as a feature of the Christian God by Saint Augustine in On the Nature of Good, written circa 399. Augustine denies the positive existence of absolute evil, describing a world with God as the supreme good at the center, and defining different grades of evil as different stages of remoteness from that center.
Experience soon teaches that all desires cannot be satisfied, that they are conflicting, and that some good must be foregone in order to secure another. Hence the necessity of weighing the relative value of good, of classifying it, and of ascertaining which good must be procured at the loss of another. The result is the division of good into two great classes, the physical and the moral, happiness and virtue. Within either class it is comparatively easy to determine the relation of particular good things to one another, but it has proven far more difficult to fix the relative excellence of the two classes of virtue and happiness. If happiness and virtue are mutually exclusive, we have to choose between the two, and this choice is a momentous one. But their incompatibility may be only on the surface. Indeed, the hope is ever recurring that the sovereign good includes both, and that there is some way of reconciling them.