Axial Age is a term coined by the German philosopher Karl Jaspers. It refers to broad changes in religious and philosophical thought that occurred in a variety of locations from about the 8th to the 3rd century BCE.

Karl Theodor Jaspers was a German-Swiss psychiatrist and philosopher who had a strong influence on modern theology, psychiatry, and philosophy. His 1913 work General Psychopathology influenced many later diagnostic criteria, and argued for a distinction between "primary" and "secondary" delusions.