Sign Capricorn, eighteen degrees
Phase Waxing gibbous
Condition Her detriment
The word to know today
Void of course
A Moon is void of course when she will form no further major aspect to a planet before leaving the sign she is in. The condition is not about her strength or her sign. It describes only that her work in that sign is done and the remaining degrees are travel.
Void of course is the condition on the record today, and it runs for nearly a full day. The Moon stands at eighteen degrees of Capricorn, waxing gibbous, and she makes no further major aspect before crossing out of the sign at 9:02 UTC tomorrow morning. That is the whole of what the term means: a Moon that has finished her business in a sign and is coasting toward the border. The writers who used it were not describing a mood.
Capricorn sits opposite Cancer. Cancer is the Moon’s domicile, the sign she rules and where she is most herself, so the sign across the wheel is her detriment, the place where she holds the least of her own authority and has to work with instruments belonging to Saturn. Cold, dry, bounded, slow to give. The Hellenistic material is consistent on this, and the Arabic and Latin writers who inherited the scheme did not soften it.
Both conditions had a specific use in horary astrology, the branch that answered a single question by casting a chart for the moment it was asked. A void Moon was among the considerations that told the astrologer to decline judgment altogether, or to judge that the matter would come to nothing. William Lilly set the rule down plainly in London in 1647, though the doctrine was old before he reached it and runs back through the medieval writers into the Greek. What a Moon like today’s was used to time was completion. The day belonged to accounts already open.
From the shelf
William Lilly, Christian Astrology
Printed at London in 1647, it is the fullest English account of the horary rules the older tradition had been carrying for centuries.

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