There has been a long standing debate between philosophers and psychologists alike as to the nature of our minds. Many used to believe that we were born tabula rasa, meaning that we were born as a 'blank slate', with nothing pre-wired into our minds. Essentialist philosophers predating those who believe in tabula rasa, used to believe that our minds were destined for a particular set of goals, immune to change. Carl Jung came along and changed everything.
This is not merely some intellectual point that has no practical value but rather a theory that can change the way you perceive yourself and others around you. You may not have thought about this consciously before but now I ask you, do you have free will? Are you in control of your actions? Do you have a destiny? If you find yourself subconsciously agreeing or disagreeing with some of the concepts above, ask yourself why? If you've studied them before then sure the answer may be simple, but if you haven't read any literature on the philosophies of free will or destiny or reality, why then can you form opinions about them instinctively? This instinct driven nature of our minds is what guided Jung to his theory on the Archetypes.
Definitions
1) The Self - Refers to the totality of ones psychic experience.
2) The Shadow - The dark side of ones personality. "The beast within."
3) The Collective Unconscious - Jung's conception that a large proportion of the unconscious mind is 'common to all mankind' resulting from the inherited structure of the brain.
Jung believed that we were not born as a 'blank slate' but rather inherited from generation to generation certain psychic remnants that remain in us all. That is not to say that we have inherited the experiences of our ancestors, we have merely inherited the very building blocks of the mind, which act in ways we cannot control.
To understand this concept better we can look at Piaget's schemata theory. How do we learn a language when we are growing up? If it truly is a new experience, in other words if our minds were a blank slate, there would be immense difficulty for toddlers and young children to learn language. Piaget observed that not only do children pick up languages quickly, they also respond to language intuitively, almost without thinking, instinctively. Therefore he concluded that there must be some mechanism (which he called schemata) that comes prebuilt in our minds to enable us to learn languages with such intuitive ease.
This is something akin to what Jung proposes. He called them the Archetypes. Eric Neumann, a student of Jung's, likened the Archetypes to psychic organs. He stated that, just like how the body has organs that operate without our knowledge so too do our minds have psychic organs that operate without our conscious awareness of them (the Archetypes). These Archetypes are common in all mankind and influence our behavior, personality, and how we experience the world. Jung once wrote "the collective unconscious appears to consist of mythological motifs or primordial images, for which reason the myths of all nations are its real exponents." Jung believes that the Archetypes cannot truly be conceptualized but that through myth and culture we can get representations of these Archetypes. For instance in Literature, an archetype is a recurring symbol or theme, like the hero archetype. Jung attempts to answer the question, "Why do we like heroes so much? Why is it a recurring symbol?" He rejects the simplistic rationale of social conditioning and superficial psychology stating that we have a desire to be better than others and be unique, but rather instead proposes that all human beings have a Hero Archetype engrained in their collective unconscious that manifests whenever we experience a related event.
A good example would be culture. One could further the argument that "If we all share common Archetypes then why are our beliefs, values, and cultures all different?" This however is missing the point. The point is not that our cultures vary but that we all live in a culture. We may have different beliefs, but we all still have beliefs. Jung believed that all our beliefs, values, and cultures were varying symbolic representations of the same Archetype. Essentially, the different symbols capture a different aspect of the Archetype. For instance our religions are drastically different but all those who adopt a religion believe in God. This, Jung believed, was because we all share a common spiritual Archetype that manifests in a conception of a divine figure. If not, then why is there tremendous similarity in religious symbols of different religions despite the fact that they were created in different places at different times? Therefore we may have different beliefs, values, and cultures, but no human being on the planet can live without all three. That inability to do so stems from the fact that all of our minds are deeply attached to Archetypes that act independently and influence our beliefs, values, and cultures.
What Does All Of This Mean?
Essentially, Jung paints a pretty bleak picture of the world. Sure we may be influenced by society, our parents, religion, etc, but deep down we are all the same. We cannot escape the human condition. Do we have free will? Although it may seem like it, we truly don't. We are governed by our Archetypes and doomed to be human, in other words we do not have the free will to be not human or super human and that has nothing to do with biological restraints so much as it has to do with psychological restraints. Therefore, a person who has committed genocide or some other grossly immoral act does so not solely because of environmental factors, but rather those environmental factors merely strengthened the Archetype within him related to such acts (Jung called this the shadow), an Archetype that is also present in all human beings. Is evil then inevitable? Is evil part of what it means to be human? Can we create our own values as Nietzsche asks of us if all of our creation stems from the same Archetype? Is the very human identity we wear all just a construct of our mind? Then is our mind separate from our reality? It's important to note that Jung allowed for an infinite number of Archetypes, all clashing and restructuring based on your conscious experience. They are fighting for superiority whenever you experience reality and from that your personality emerges, not because you willed it but because the Archetypes have changed their hierarchy. Every interaction, every moment awake, every glaring breath of reality and your Archetypes change their formulation to shift your personality, your behavior, your mood, your reality. They are Gods enslaving you to 'freedom'.