The meaning of life constitutes a philosophical question concerning the purpose and significance of human existence. This concept can be expressed through a variety of related questions, such as Why are we here?, What's life all about? and What is the meaning of it all? It has been the subject of much philosophical, scientific, and theological speculation throughout history. There have been a large number of answers to these questions from many different cultural and ideological backgrounds. Albert Camus observed, we humans are creatures who spend our lives trying to convince ourselves that our existence is not absurd.
What is the meaning of life and why are we here? That's a question that has been asked for many years. The meaning of life is deeply mixed with the philosophical and religious conceptions of existence, consciousness, and happiness, and touches on many other issues, such as symbolic meaning, ontology, value, purpose, ethics, good and evil, free will, conceptions of God, the existence of God, the soul and the afterlife.
Scientific contributions are more indirect; by describing the empirical facts about the universe, science provides some context and sets parameters for conversations on related topics. An alternative, human-centric, and not a cosmic/religious approach is the question "What is the meaning of my life?" The value of the question pertaining to the purpose of life may be considered to be coincidal with the achievement of ultimate reality, if that is believed by one to exist. Science may or may not be able to tell us what is of essential value in life, but some studies bear on related questions: researchers in positive psychology (and, earlier and less rigorously, in humanistic psychology) study factors that lead to life satisfaction, full engagement in activities, making a fuller contribution by utilizing one's personal strengths, and meaning based on investing in something larger than the self.
One value system suggested by social psychologists, broadly called Terror Management Theory, states that all human meaning is derived out of a fundamental fear of death, whereby values are selected when they allow us to escape the mental reminder of death. Neuroscience has produced theories of reward, pleasure and motivation in terms of physical entities such as neurotransmitter activity, especially in the limbic system and the ventral tegmental area in particular. If one believes that the meaning of life is to maximize pleasure, then these theories give normative predictions about how to act to achieve this. Economists have learned a great deal about what is valued in the marketplace; and sociology examines value at a social level using theoretical constructs such as value theory, norms, anomie, etc.