The conjunction Ketu + Mercury
If Mercury is strong, the combination Ketu + Mercury gives inborn Mercurial talents, unconventional thinking and a gift for languages. If Mercury is weak, it may give nervous breakdowns, hinder the work of the mind, produce mistakes in calculations, and make the person a cunning scoundrel.
Ketu + Mercury may produce a quiet genius whose mind is turned inward, or a fault-finder who is displeased with everything yet cannot understand the causes of his displeasure, since his mind (Mercury) is dispersed by the energy of Ketu.
If Mercury is strong, this combination gives a deep understanding of the indications of the house in which it takes place.
An example: a popular preacher (Jupiter in the 10th) and singer (the Moon in the 2nd house of speech under an aspect of Jupiter). Ketu stands with Mercury, Saturn, Venus and the Sun in Virgo in the 5th house.
On the one hand the native has many inborn talents: a natural leader — Ketu + the Sun; a master of many languages — Ketu + Mercury; a hard worker — Ketu + Saturn; a good player of musical instruments and a singer — Ketu + Venus; able to invest money wisely (Ketu in the 5th house). But on the other hand Ketu also led him to reject everything and to take monastic vows — that is, to commit a «social suicide».
(from the materials of Vasily Tushkin’s «Surya-Siddhanta» school)
The influence of Ketu => Mercury
Mercury is stronger than Ketu — a high level of intellect in exchange for a closing off in outward contacts. It is hard to stop the thinking process. In a short stretch of time the person analyses enormous arrays of information. Excellent managers, market analysts and traders.
Mercury is weaker than Ketu — complexes and blocks in communication. Speech may be afflicted. Stammering is possible. An inability to express one's inner state.
The influence of Mercury => Ketu
They know the value of their ideas, emotions and inner values. They think constantly about their material plans and ideas, but often cannot bring them into reality. Great difficulties in the spiritual life, since the whole inner space is taken up by materialism. Dealings with wise and deeply spiritual people are strongly recommended.
(Roman Gavrilov)