Jung's 'Platonic' Month
Definition: [Astrological Ages] Exactly one-twelfth of a Great Year. The length of a 'Platonic' month equals 2160.4 years. [2002 AD] The term appears to have first been coined by Carl Gustav Jung in Aion - where, in footnote 84, he gives us its calculated length: 2 143 years. Two centuries earlier Voltaire had proposed the concept, but not given it this name.
How did Jung Calculate the time span of a 'Platonic' Month? This can be calculated - as Jung did - from the precessional rate, as follows. In Aion, Jung used a precessional rate of 50.3608 arc seconds per year [an arc second is one-sixtieth of one-sixtieth of a degree]. This he took as the angle by which the Vernal Equinox Point changes, as seen against the stars, each year. Divide that angle into the full circle of 360º and you have the number of years which it would take to make a complete precessional cycle: 25 734.3 years. Divide that number of years by 12 for a "Platonic" month and you get 2 144.5 years - Jung's math is out by a year.
However, the techniques to measure precession are now much more accurate than they were in the 1940s. The currently accepted value of the precessional rate [2002 AD] is 49.989 arc seconds per year, a fraction less than the one Jung was using. This gives a 'Platonic' month of 2 160.4 years and a Great Year of 25 925 years.
Is a 'Platonic' Month Equal to an Astrological Age? No. However, this question has excited a lot of debate amongst astrologers and quite a few would say that the answer to that question was "yes." If your particular answer to this question is "yes," then the calculation of the date of the beginning of the next Astrological Age, the Age of Aquarius, is normally done as follows... Simply add 2160.4 years on to the date on which the Age of Pisces began. [See New Ages for dates ranging between 2000 and 2100 AD calculated using this approach. Even Jung himself, in Aion [C G Jung Aion Chapter IV, The Sign of the Fishes, Footnote 84, 1951 AD ] had a go at this same calculation, coming up with dates between 1997 and 2154 AD.]
Of course, even if you believe that this is the right way to find the start of the Age, the problem with this approach is... when did the Age of Pisces begin? This depends on where the constellation border lies between Pisces and Aries. The logical flaw here is obvious: the original Aries-Pisces boundary is a stellar one, not based on "Platonic" Months. How can you use one type of boundary for one Age and another type of boundary for the next? Of course the answer is that logically you can't. It doesn't work.
Why is a 'Platonic' Month Not Equal to an Astrological Age? Because of the definition of an Astrological Age. Jung stated that "it refers to the actual constellation of fixed stars, not to ... the zodiac divided into sectors of 30º each." The Real Solar Zodiac constellations have two properties which rule out a 'Platonic' Month being an Astrological Age: first, there are thirteen of them; secondly, they are all different sizes, not "sectors of 30º each." . [See Astrological Age for more information on this.]
In modern astrological terms, we would say that the Vernal Equinox Point moves against the Real Solar Zodiac, i.e. the actual heavens, rather than the Tropical Zodiac. That Jung based the entire astrological New Age concept on the Real Solar Zodiac is shown by, for example, paragraph 149 of Aion, where Jung looks for 'synchronicity' between world events and the movement of the Vernal Equinox Point through the real stars of the second fish of the constellation of Pisces. The Tropical Zodiac Pisces sign of Western astrology plays no role - in fact by definition it can not, as in the Tropical Zodiac the Vernal Equinox Point never moves through the sign of Pisces, it stays still at the begining of Aries. This Jung is well aware of. He states in paragraph 7 of The Archetypes and the Collective Unconsciousness: "And yet anyone who can cast a horoscope should know that, since the days of Hipparchus of Alexandria, the spring-point has been fixed at 0º Aries, and that the zodiac on which every horoscope is based is therefore quite arbitrary, the spring-point having gradually advanced, since then, into the first degree of Pisces owing to the precession of the equinoxes." Jung here is writing here exclusively of the Tropical Zodiac. The various Sidereal Zodiacs specifically take into account precession, as naturally - as it's based on the real heavens - does the Real Solar Zodiac.
The description of the Vernal Equinox Point as now within the "first degree of Pisces," sounds somewhat confusing. Jung here is referring to the Sidereal Zodiac of equal 30º divisions of the heavens. In this Zodiac, which is quite close to the reality of the heavens, the Vernal Equinox Point is now very close to the end of the Sidereal Sign of Pisces. He is not talking about the real constellations, the Real Solar Zodiac, on which he bases his concept of the Astrological Age.
Jung in Footnote 84 in Aion notably confuses the Sidereal Zodiac with the Real Solar Zodiac, otherwise he wouldn't have attempted to make that calculation I refer to above. This is somewhat strange, as he is very explicit that the Astrological Age concept refers to the actual constellations - see below. I do wonder whether Jung, having come to believe in the validity of Astrological Ages, then found it difficult to stomach the fact that the next one wouldn't arrive for another 600 years by his own definition [see Age of Aquarius]. From his footnotes in Aion, we know he had a copy of Ptolemy's Star Catalog and could easily have worked out this approximate date for himself. In 2154 AD the Vernal Equinox Point is still very firmly within the constellation of Pisces [see Movement of the Vernal Equinox Point.]. A more charitable explanation is that he didn't know enough about the stars to know that the Constellations had different sizes - Pisces is in fact greater than 35º of the Ecliptic in length - nor about the issue of Ophiuchus. He was, after all, first and foremeost a pyschoanalyst, not an astrologer. Either way, in this respect we live with Jung's legacy: wishing for a New Age which hasn't arrived.
Why is it called a 'Platonic' Month? It should be noted that the concept of a Great Month appears nowhere in the writings of Plato [427 - 347 BC]. This isn't too surprising because neither does the concept of an equal-sign Solar Zodiac, [nor indeed any Zodiac at all] without which - as noted above - the concept of Great Month could not exist. It has been argued that by using the term 'Platonic' Month, Jung inaccurately projected a concept back onto Plato, which there is no evidence that Plato ever possessed.
To follow Jung's reasoning for the use of the prefix 'Platonic' see the 'Platonic' Year page.
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© Dr Shepherd Simpson, Astrological Historian
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