The Buddha argued that compounded entities lacked essence, correspondingly the self is without essence. This means there is no part of a person which is unchanging and essential for continuity, and it means that there is no individual "part of the person that accounts for the identity of that person over time". This is in opposition to the Upanishadic concept of an unchanging ultimate self (Atman) and any view of an eternal soul. The Buddha held that attachment to the appearance of a permanent self in this world of change is the cause of suffering, and the main obstacle to liberation.