Jung credited Freud for his discoveries in the field of neurosis but he was not without criticism for his former tutor. In Jung’s view, Freud cleared a lot of ground for future psychologists, but only as far as basic physiological concepts permitted. Psychology was viewed by Freud as an offshoot of the physiology of the instincts.
Jung was bothered by this because he believed that there was more to psychology than mere materialism, and rather than accept the excuse to not bother exploring outside the domain of the physiological, Jung ventured beyond the confines of Freud’s theories. Jung believed that archetypal images had no relations to the physical reality of the individual.
It isn’t that when you dream and conjure up primordial images, that this is just your brain processing your life experiences, their source is deeper than that. You have inherited them from your ancestors.
These forms are generally supposed to be transmitted by tradition, so that we speak of “atoms” today because we have heard, directly or indirectly, of the atomic theory of Democritus. But where did Democritus, or whoever first spoke of minimal constitutive elements, hear of atoms? This notion had its origin in archetypal ideas, that is, in primordial images which were never reflections of physical events but are spontaneous products of the psychic factor. Despite the materialistic tendency to understand the psyche as a mere reflection or imprint of physical and chemical processes, there is not a single proof of this hypothesis. Quite the contrary, innumerable facts prove that the psyche translates physical processes into sequences of images which have hardly any recognizable connection with the objective process. The materialistic hypothesis is much too bold and flies in the face of experience with almost metaphysical presumption. The only thing that can be established with certainty, in the present state of our knowledge, is our ignorance of the nature of the psyche.