Thought encompasses an "aim-oriented flow of ideas and associations that can lead to a reality-oriented conclusion". Although thinking is an activity of an existential value for humans, there is still no consensus as to how it is adequately defined or understood. Because thought underlies many human actions and interactions, understanding its physical and metaphysical origins and its effects has been a longstanding goal of many academic disciplines including philosophy, linguistics, psychology, neuroscience, artificial intelligence, biology, sociology and cognitive science. Thinking allows humans to make sense of, interpret, represent or model the world they experience, and to make predictions about that world. It is therefore helpful to an organism with needs, objectives, and desires as it makes plans or otherwise attempts to accomplish those goals.