In Nietzschean philosophy, as well as in Freudian psychoanalytic theory, sublimation is the redirection of negative emotions and repressed, unconscious drives (in Freud) or a suppressed will to power (Nietzsche) to creative, healthy outlets, often either artistic or spiritual. Also, in chemistry, sublimation is the process by which solids are transformed directly to the vapor state without passing through the liquid phase. Example: Dry ice (solid carbon dioxide) changes directly to carbon dioxide gas without passing through a liquid state.