The “archetype” is practically synonymous with the biological concept of the behaviour pattern. But as the latter designates external phenomena chiefly, I have chosen the term “archetype” for “psychic pattern”. We don’t know whether the weaver-bird beholds a mental image while it follows an immemorial and inherited model in building its nest, but there is no doubt that no weaver-bird in our experience has ever invented its nest. It is as if the image of nest-building were born with the bird.

As no animal is born without its instinctual patterns, there is no reason whatsoever to believe that man should be born without his specific forms of physiological and psychological reactions. As animals of the same kind show the same archetypal forms all over the world, man also shows the same archetypal forms no matter where he lives. As animals have no need to be taught their instinctive activities, so man also possesses his primordial psychic patterns and repeats them spontaneously, independently of any kind of teaching. Inasmuch as man is conscious and capable of introspection, it is quite possible that he can perceive his instinctual patterns in the form of archetypal representations. As a matter of fact, these possess the expected degree of universality.

(C.G. Jung, Letters, vol. 2: 1951-1961 / 13. 2. 1954, Letter to Prof. G.A. van den Bergh van Eysinga / p. 151 f / italics in the original text)

Accordingly, ego-consciousness seems to be dependent on two factors: firstly, on the condition of the collective, i.e., the social, consciousness; and secondly, on the archetypes, or the dominants, of the collective unconscious. The latter fall phenomenologically into two categories: instinctual and archetypal. The first includes the natural impulses, the second the dominants that emerge into consciousness as universal ideas.

(C.G. Jung, Collected Works, vol. 8 / On the Nature of the Psyche / 1946, 1954 / § 423)

Judging by all we know about [complexes], they are psychic entities which are outside the control of the conscious mind. They have been split off from consciousness and lead a separate existence in the dark realm of the unconscious, being at all times ready to hinder or reinforce the conscious functioning.

(C.G. Jung, Collected Works, vol. 6 / A Psychological Theory of Types / 1921, 1931 / § 923)

They are the “sore spots”... They always contain memories, wishes, fears, duties, needs, or insights which somehow we can never really grapple with, and for this reason they constantly interfere with our conscious life in a disturbing and usually a harmful way.

(C.G. Jung, Collected Works, vol. 6 / A Psychological Theory of Types / 1921, 1931 / § 924)

Complexes obviously represent a kind of inferiority in the broadest sense – a statement I must at once qualify by saying that to have complexes does not necessarily indicate inferiority. It only means that something discordant, unassimilated, and antagonistic exists, perhaps as an obstacle, but also as an incentive to greater effort, and so, perhaps, to new possibilities of achievement. In this sense, therefore, complexes are focal or nodal points of psychic life which we would not wish to do without; indeed, they should not be missing, for otherwise psychic activity would come to a fatal standstill. They point to the unresolved problems in the individual, the places where he has suffered a defeat, at least for the time being, and where there is something he cannot evade or overcome – his weak spots in every sense of the word.

(C.G. Jung, Collected Works, vol. 6 / A Psychological Theory of Types / 1921, 1931 / § 925)

Everyone knows nowadays that people “have complexes”. [...] What is not so well known, though far more important theoretically, is that complexes can have us. The complex must therefore be a psychic factor which, in terms of energy, possesses a value that sometimes exceeds that of our conscious intentions; otherwise such disruptions of the conscious order would not be possible at all. And in fact, an active complex puts us momentarily under a state of duress, of compulsive thinking and acting, for which under certain conditions the only appropriate term would be the judicial concept of diminished responsibility.

(C.G. Jung, Collected Works, vol. 8 / A Review of the Complex Theory / 1934 / § 200 / italics in the original text)

The spectacle [of differences of temperament] made me ponder the question: are there at least two different human types, one of them more interested in the object, the other more interested in himself? 

(C.G. Jung, Collected Works, vol 7 / The Problem of the Attitude-Type / 1916, 1942 / § 61)

I have long busied myself with this question and have finally, on the basis of numerous observations and experiences, come to postulate two fundamental attitudes, namely introversion and extraversion. The first attitude is normally characterized by a hesitant, reflective, retiring nature that keeps itself to itself, shrinks from objects, is always slightly on the defensive and prefers to hide behind mistrustful scrutiny. The second is normally characterized by an outgoing, candid, and accommodating nature that adapts easily to a given situation, quickly forms attachments, and, setting aside any possible misgivings, will often venture forth with careless confidence into unknown situations. In the first case obviously the subject, and in the second the object, is all-important.

(C.G. Jung, Collected Works, vol. 7 / The Problem of the Attitude-Type / 1916, 1942 / § 62)

Extraversion and introversion... decides whether the conscious contents refer to external objects or to the subject. Therefore, it also decides whether the value stressed lies outside or inside the individual. This modality operates so persistently that it builds up habitual attitudes, that is, types with recognizable outward traits.

(C.G. Jung, Collected Works, vol. 8 / Psychological Factors in Human Behaviour / 1929 / §250)

The shadow is a moral problem that challenges the whole ego-personality, for no one can become conscious of the shadow without considerable moral effort. To become conscious of it involves recognizing the dark aspects of the personality as present and real. This act is the essential condition for any kind of self-knowledge, and it therefore, as a rule, meets with considerable resistance. Indeed, self-knowledge as a psychotherapeutic measure frequently requires much painstaking work extending over a long period. 

(C.G. Jung, Collected Works, vol. 9/II / The Shadow / 1951 / § 14)

The shadow [is] that hidden, repressed, for the most part inferior and guilt-laden personality whose ultimate ramifications reach back into the realm of our animal ancestors and so comprise the whole historical aspect of the unconscious.

(C.G. Jung, Collected Works, vol. 9/II / Chapter XV: Conclusion / 1951 / § 422)

[On closer investigation we can see, that the] shadow does not consist only of morally reprehensible tendencies, but also displays a number of good qualities, such as normal instincts, appropriate reactions, realistic insights, creative impulses etc. 

(C.G. Jung, Collected Works, vol. 9/II / Chapter XV: Conclusion / 1951 / § 423)

(The individuation-process) is, in effect, the spontaneous realization of the whole man. The ego-conscious personality is only a part of the whole man, and its life does not yet represent his total life. The more he is merely “I”, the more he splits himself off from the collective man, of whom he is also a part, and may even find himself in opposition to him. But since everything living strives for wholeness, the inevitable one-sidedness of our conscious life is continually being corrected and compensated by the universal human being in us, whose goal is the ultimate integration of conscious and unconscious, or better, the assimilation of the ego to a wider personality.

(C.G. Jung, Collected Works, vol. 8 / On the Nature of Dreams / 1945 / § 557)

The individual as the [...] carrier of life and existence is of paramount importance... What we need is the development of the inner spiritual man, the unique individual whose treasure is hidden on the one hand in the symbols of our mythological tradition, and on the other hand in man’s unconscious psyche. 

(C.G. Jung, Letters, vol. 2: 1951-1961 / 7. 1. 1955 /Letter to Upton Sinclair / p. 207)

I chose this term [synchronicity] because the simultaneous occurrence of two meaningfully but not causally connected events seemed to me an essential criterion. I am therefore using the general concept of synchronicity in the special sense of a coincidence in time of two or more causally unrelated events which have the same or a similar meaning, in contrast to “synchronism”, which simply means the simultaneous occurrence of two events.

(C.G. Jung, Collected Works, vol. 8 / Synchronicity: An Acausal Connecting Principle / 1952 / § 849)

Synchronicity therefore means the simultaneous occurrence of a certain psychic state with one or more external events which appear as meaningful parallels to the momentary subjective state – and, in certain cases, vice versa. 

(C.G. Jung, Collected Works, vol. 8 / Synchronicity: An Acausal Connecting Principle / 1952 / § 850)

Psyche cannot be totally different from matter, for how otherwise could it move matter? And matter cannot be alien to psyche, for how else could matter produce psyche? Psyche and matter exist in one and the same world, and each partakes of the other, otherwise any reciprocal action would be impossible.

(C.G. Jung, Collected Works, vol. 9/II / The Structure and Dynamics of the Self / 1951 / § 413)

Sooner or later nuclear physics and the psychology of the unconscious will draw closer together as both of them, independently of one another and from opposite directions, push forward into transcendental territory, the one with the concept of the atom, the other with that of the archetype.

(C.G. Jung, Collected Works, vol. 9/II / The Structure and Dynamics of the Self / 1951 / § 412)

The psyche is a self-regulating system that maintains its equilibrium just as the body does. Every process that goes too far immediately and inevitably calls forth compensations, and without these there would be neither a normal metabolism nor a normal psyche. In this sense we can take the theory of compensation as a basic law of psychic behaviour.

(C.G. Jung, Collected Works, vol. 16 / The Practical Use of Dream-Analysis / 1931, 1947 / § 330)

From all this it should now be clear why I make it a heuristic rule, in interpreting a dream, to ask myself: What conscious attitude does it compensate? By so doing, I relate the dream as closely as possible to the conscious situation; indeed, I would even assert that without knowledge of the conscious situation the dream can never be interpreted with any degree of certainty. Only in the light of this knowledge is it possible to make out whether the unconscious content carries a plus or a minus sign. The dream is not an isolated event completely cut off from daily life and lacking its character. If it seems so to us, that is only the result of our lack of understanding, a subjective illusion. In reality the relation between the conscious mind and the dream is strictly causal, and they interact in the subtlest of ways.

(C.G. Jung, Collected Works, vol. 16 / The Practical Use of Dream-Analysis / 1931, 1947 / § 334)

That is why every dream is an organ of information and control, and why dreams are our most effective aid in building up the personality.

(C.G. Jung, Collected Works, vol. 16 / The Practical Use of Dream-Analysis / 1931, 1947 / § 332)