Since it's discovery in 1930 Pluto has progressed from 17 degrees 46 Cancer to 07 degrees 30 Capricorn, not yet half an orbit. This is the only period that we have DIRECT knowledge of Pluto and any possible Astrological effect. Of course it is objected that we can (and indeed do) correlate Pluto's previous positions with historical data. Any scientist knows that there is all the world of difference between Primary data - direct observation - and secondary data - the use of previously recorded data, not least because the latter has issues of accuracy and relevance. Unless we keep diaries over our life times, it's even difficult to recall accurately what happened 10 years ago, except for some events that stick in our mind but the rest is lost. All historical records are selective and incomplete, at best they may be used to corroborate current observations.
Now this of course does not disprove Pluto, it merely raises a fnoteof caution. in relation to retrospective analysis.
However even the volume of charts and writings, do not show much in the way of a development of Pluto's interepretation - it's Astrological meaning seems to have been established very quickly within the first 5 or 6 years. Brunhubner had produced a 'comprehensive' guide to the new planet as early as 1933 and in 1937 despite a note of caution Harrison defines Pluto as:
'A planet of action that signifies an attempt to throw off the accumulations that have resulted from the lethargy of Neptune and a desire to be free of the bonds the latter has imposed....It is therefore violent in its effects, which explains it's now known connection with illness and accidents. as well as its presence and import in the maps of musicians and the spiritually inclined on the one hand and the maps of criminals on the other. It is eruptive in nature and suggests freedom and explosive action'
Raymond Harrison, The Measure Of Life, 2nd edition. 1937
Clearly the volume of charts and writings had already reached a conclusion before 1937 and perhaps as early as 1933.
In part this was due to the hypothetical planets mentioned by Dave, one of which was called 'Pluto' and was advanced by Maurice Wemyss - Theosophist Astrologers had set their sights on 12 planets one ruler for each sign. They had even discussed which sign hypothetical Pluto ruled - some seeing Cancer, others seeing Scorpio.
There is though a more serious issue here and one which I don't see a solution to (at least in the short term). The Astrological Association of Great Britain claims that Astrology is a science, or at least a discipline, the rules of which can be taught to anyone who is then able to apply them.
However this is a great over simplification. Rules and procedures are indeed part of the process but a key part is the Astrologer him or herself. Astrology is an Art and the Artist skill is important but also his or her Weltanschaaung - philosophy and outlook on life.
Since the beginning of the twentieth Century the dominant Astrological orthodoxy has been based on Theosophical principles as extended and developed by principles based on the psychology of Jung. Uranus, Neptune and especially Pluto have been introduced into Astrology on the basis of these beliefs and indeed have in turn contributed to the establishment of these beliefs - to question Pluto is to question the Credo of modern Astrology and no orthodox Astrologer is going to do this. Eventually the orthodoxy will change and give way to a new one, that process may even have begun but in the meantime Pluto will still be essential to the mainstream Astrologer.
The key issue then, is not so much about the nature of Pluto but about your approach to and philosophy of Astrology. That Astrology can be still practiced without Pluto (or Uranus, Neptune, Chiron, etc) is shown by the work of Vedic Astrologers and Traditional Western Astrologers but neither of these will conform to the expectations of the Astrologer rooted in Jung and Rudhyar, etc. I don't have a problem with that and I certainly don't want to deny Dave or any other Astrologer their use of Pluto. I simply want them to be aware that there is Astrology without Pluto and that some caution about Pluto might not be a bad thing.
When it comes to the Chiron,asteroids, plutoids, Kuyper belt objects and indeed hypothetical planets, there is clearly two problems at least - the first is a Plutoesque rush to include them without proper consideration and the second, and even more important problem is the interrelationship of these objects both to the other established planets and to the process of Astrological interpretation. Simply bolting on new objects piecemeal is a recipe for confusion and eventual disaster, (and certainly the undermining of Astrology as a disciplined pursuit of knowledge). I think actually Dave agrees with me on that general point - a coherent methodology placed in the context of a clear philosophy is needed and there are certainly more than one way of achieving that aim.
