What is an Archetype?

This is certainly not an exhaustive resource, but I will add to it as I come across useful references. Of course for the best understanding, reading Jung’s writings in full context is second to none. New additions will be added to the top of the list and typed in bold. CW = collected works of Carl Jung

Update May 21, 2020: Added quotes from Erich Neumann’s The Origins and History of Consciousness and On Divination and Synchronicity by Mary-Louise von Franz.

• “The structural elements of the collective unconscious are named by Jung “archetypes” or “primordial images.” They are the pictorial forms of the instincts, for the unconscious reveals itself to the conscious mind in images which, as in dreams and fantasies, initiate the process of conscious reaction and assimilation.” – Erich Neumann, The Origins and History of Consciousness
• “In the collective unconscious all archetypes are contemporaneous, and exist side by side. Only with the development of consciousness do we come to a graduated hierarchy within the collective unconscious itself.” – Erich Neumann, The Origins and History of Consciousness
• “Archetypal images are operating in every man and appear spontaneously whenever the layer of the collective unconscious is activated.” – Erich Neumann, The Origins and History of Consciousness
• “When instincts are centrally represented, i.e., when they appear as images, Jung calls them archetypes. Archetypes take the form of images only where consciousness is present.; in other words, the plastic self-portrayal of instincts is a psychic process of a higher order. It presupposes an organ capable of perceiving these primordial images. This organ is consciousness, which on that account is associated with the eye, light, and sun symbols, so that in mythological cosmogony the origin of consciousness and the coming of the light are one and the same.” – Erich Neumann, The Origins and History of Consciousness p. 295
• “It is as though the world of the unconscious were, in effect, an extension of the numinous, as though the inconceivable multiplicity of its aspects had been divided up into the separate figures of the collective unconscious, in order to become experienceable for the ego, either successively or in the aggregate… the collective unconscious is split up into the pictorial world of the archetypal images, and the same line of development leads to the fragmentation of the archetypes themselves.” – Erich Neumann, The Origins and History of Consciousness p. 321 
• “The original unity breaks down into a solar system of archetypes and symbols grouped round a nuclear archetype, and the archetypal nexus of the collective unconscious comes forth from the darkness into light.” –  Erich Neumann, The Origins and History of Consciousness p. 326
• “Again, just as the digestive system decomposes food into its basic elements, so consciousness breaks up the great archetype into archetypal groups and symbols which can later be assimilated as split-off attributes and qualities by the perceptive and organizing powers of the conscious mind.” – Erich Neumann, The Origins and History of Consciousness p. 326
• “The kind of experience we shall have is prescribed by the archetypes, but what we experience is always individual.” – Erich Neumann, The Origins and History of Consciousness p. 349
• “Jung defines the archetypes as being the nuclear dynamisms of the psyche. Each archetype is also like a mass of dynamic energy.” – On Divination and Synchronicity, Marie-Louise von Franz
• “The archetype could therefore be defined as a structure which conditions certain psychological probabilities” – On Divination and Synchronicity, Marie-Louise von Franz
• “Since our most basic psychological structure is formed by the archetypes which means generally collective patterns of behaviour, we all tend to react in the same way in certain situations.” – On Divination and Synchronicity, Marie-Louise von Franz
• “If one knows enough mythology one can make a completely consistent web from every great archetype to every other great archetype. There is always a legend or a saga which links up two archetypes in a new form, and it is a tragedy people do not realize that.” – On Divination and Synchronicity, Marie-Louise von Franz

• “Just as conscious apprehension gives our actions form and direction, so unconscious apprehension through the archetype determines the form and direction of instinct” – Carl Jung CW vol 8 par 277
• a primordial image that is “instinct’s perception of itself, or as the self-portrait of instinct” – Carl Jung CW vol 8 par 277
• “The instincts and the archetypes together form the ‘collective unconscious’” – Carl Jung CW vol 8 par 277
• “Just as the archetypes occur on the ethnological level as myths, so also they are found in every individual, and their effect is always strongest, that is, they anthropomorphize reality most, where consciousness is weakest and most restricted, and where fantasy can overrun the facts of the outer world.” – Carl Jung, CW vol 9i, par 136
• “a group of related or analogous psychic phenomena” – Carl Jung, CW vol 9i, par 114
• contents of the collective unconscious, primordial images, mythological motifs
• “The archetype is essentially an unconscious content that is altered by becoming conscious and by being perceived, and it takes its colour from the individual consciousness in which it happens to appear.” – Carl Jung, CW vol 9i, par 7
• “There is good reason for supposing that the archetypes are the unconscious images of the instincts themselves, in other words, they are patterns of instinctual behaviour.” – Carl Jung, CW vol 9i, par 93
• “All ages before us have believed in gods in some form or another. Only an unparalleled impoverishment of symbolism could enable us to rediscover the gods as psychic factors, that is, as archetypes of the unconscious.” – Carl Jung, CW vol 9i, par 50
• “Archetypes are complexes of experiences that come upon us like fate, and their effects are felt in our most personal life.” – Carl Jung, CW vol 9i, par 62
• “As organs of the psyche’s structure the archetypes articulate with one another, like physical organs, and determine the maturation of the personality in a manner analogous to the biological hormone-components of physical constitution.” – Erich Neumann, The Origins and History of Consciousness
• Definite forms of the psyche, present always and everywhere

This is a living document. Will update as I come across more information.
See also What is the Collective Unconscious?

-Ryan; Last updated 5/21/2020

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