Carl Jung’s letter to M. Barbault on Astrology:

Dear M. Barbault:

First I must apologize for being so late in answering your letter of March 19th. I was away on holiday part of the time or else ill. Besides, unfortunately, my advanced age no longer permits me to fulfill all my obligations as I would like to.

As for your questionnaire, here are my answers:

1. The connections between astrology and psychology.

There are many instances of striking analogies between astrological constellations and psychological events or between the horoscope and the characterological disposition. It is even possible to predict to a certain extent the psychic effect of a transit.

For example [Astrological Symbols not included]…One may expect with a fair degree of probability that a given well-defined psychological situation will be accompanied by an analogous astrological configuration, Astrology, like the collective unconscious with which psychology is concerned, consists of symbolic configurations: the “planets” are the gods, symbols of the powers of the unconscious.

2. The modus operandi of Astrological Constellations. It seems to me that it is primarily a question of that parallelism or “sympathy” which I call synchronicity, an acausal connection expressing relationships That cannot be formulated in terms of causality, such as precognition, premonition, psychokinesis, and also what we call telepathy. Since causality is a “statistical truth,” there are exceptions of an acausal nature bordering on the category of synchronistic (not synchronous) events. They have to do with “qualitative time.”

3. Attitude to positions taken by astrologers [etc.]. The first experiences in life owe their specific (pathogenic) effect to environmental influences on the one hand, and on the other to psychic predisposition, i.e. to heredity, which seems to be expressed in a recognizable way in the horoscope. The latter apparently corresponds to a definite moment in the colloquy of the gods. That is to say the psychic archetypes.

4. Qualitative Time. This is a notion I used formerly but I have replaced it with the idea of synchronicity, which is analogous to sympathy or correspondentia, or to Leibniz’s pre-established harmony. Time in itself consists of nothing. It is only a modus cogitandi that is used to express and formulate the flux of things and events, just as space is nothing but a way of describing the existence of a body.

When nothing occurs in time, and when there is no boy in space, there is neither time nor space. Time is always and exclusively “qualified” by events as space is by the extension f bodies. But “qualitative time” is a tautology and means nothing, whereas synchronicity (not synchronism) expresses the parallelism and analogy between events in so far as they are non-causal. In contrast, “qualitative time” is an hypothesis that attempts to explain the parallelism of events in terms of causa et effectus. But since qualitative time is nothing but the flux of things, and is moreover just as much “nothing” as space, this hypothesis does not establish anything except the tautology: the flux of things and events is the cause of the flux of things, etc.

Synchronicity does not admit causality in the analogy between terrestrial events and astrological constellations (except for the deflection of solar protons and their possible effect on terrestrial events), and denies it particularly in all cases of nonsensory perception (ESP), especially precognition, since it is inconceivable that one could observe the effect in a nonexistent cause, or of a cause that does not exist.

What astrology can establish are the analogous events, but not that either series is the cause or effect of the other. (For instance, the same constellation may at one time signify a catastrophe and other time, in the same case, a cold in the head.) Nevertheless, astrology is not an entirely simple matter. There is that deflection of solar protons cause on the one hand by the conjunctions, oppositions, and quartile aspects, and on the other hand by the trine and sextile aspects, and their influence on the radio and many other things. I am not competent to judge how much importance should be attributed to this possible influence.

In any case, astrology occupies a unique and special position among the intuitive methods, and in explaining it there is reason to be dubious of both a causal theory and the exclusive validity of the synchronistic hypothesis.

5. I have observed many cases where a well-defined psychological phase, or an analogous event, was accompanied by a transit (particularly when Saturn and Uranus were effected).

6. My main criticisms of astrologers. If I were to venture an opinion in a domain with which I am only very superficially acquainted, I would say that the astrologer does not always consider his statement to be mere possibilities. The interpretation is sometimes too literal and not symbolic enough, also too personal. What the zodiac and the planets represent are not personal traits; they are impersonal and objective facts. Moreover, several “layers of meaning” should be taken into account in interpreting the Houses.

7. Obviously astrology has much to offer psychology, but what the latter can offer its elder sister is less evident. So far as I can judge, it would seem to me advantageous for astrology to take the existence of psychology into account, above all the psychology of the personality and of the unconscious. I am almost sure that something could be learnt from it symbolic method of interpretation; for that has to do with the interpretation of the archetypes (the gods) and their mutual relations, the common concern of both arts. The psychology of the unconscious is particularly concerned with archetypal symbolism.

Hoping you will find this answer satisfactory, I remain,

Yours sincerely, C.G. Jung

Letter dated May 26, 1954