 The two factors that supply the fuel and the motive force in all sustained endeavours are - "buddhi" ('understanding') and "dhrti" ('fortitude'), the former is 'the intellectual capacity to grasp what is happening' and the latter is 'the constancy of purpose and self-application'.Abhinavagupta states that since everyone works therefore, everyone possesses "dhrti"; he holds "buddhi" to mean 'resolution' and "dhrti" to mean 'satisfaction'.In Hinduism, four things viz.