The self in any culture looks out for its well being and will avoid as much threat as possible. This can be explained through the evolutionary psychology concept called survival of the fittest. The philosophy of self seeks to describe essential qualities that constitute a person's uniqueness or essential being. There have been various approaches to defining these qualities. The self can be considered that being which is the source of consciousness, the agent responsible for an individual's thoughts and actions, or the substantial nature of a person which endures and unifies consciousness over time. In addition to Emmanuel Levinas writings on "otherness", the distinction between "you" and "me" has been further elaborated in Martin Buber's philosophical work: Ich und Du.  Religious views on the self vary widely. The self is a complex and core subject in many forms of spirituality. Two types of self are commonly considered—the self that is the ego, also called the learned, superficial self of mind and body, an egoic creation, and the self which is sometimes called the "True Self", the "Observing Self", or the "Witness". In Hinduism, the Ātman (self) is not an individual, but a representation of the transcendent reality Brahman. One description of spirituality is the self's search for "ultimate meaning" through an independent comprehension of the sacred. Another definition of spiritual identity is: "A persistent sense of self that addresses ultimate questions about the nature, purpose, and meaning of life, resulting in behaviors that are consonant with the individual’s core values. Spiritual identity appears when the symbolic religious and spiritual value of a culture is found by individuals in the setting of their own life. There can be different types of spiritual self because it is determined by one's life and experiences." Human beings have a self—that is, they are able to look back on themselves as both subjects and objects in the universe. Ultimately, this brings questions about who we are and the nature of our own importance. Traditions such as Buddhism see the attachment to self is an illusion that serves as the main cause of suffering and unhappiness. Christianity makes a distinction between the true self and the false self, and sees the false self negatively, distorted through sin: 'The heart is deceitful above all things, and desperately wicked; who can know it?' (Jeremiah 17:9)  According to Marcia Cavell, identity comes from both political and religious views. He also identified exploration and commitment as interactive parts of identity formation, which includes religious identity.