To the ancient astrological literature of the Hindus traced to Sage Parasara there belong a certain number of complementary works without whose assistance, the student of astrology may not be able to understand the deeper implications of the subject.
Prasna Margam may be considered as one such work. It is an exhaustive treatise on the various aspects of Prasnam or Horary astrology. This work can be considered as of exceptional interest and value. The authorship of the work is attributed to a Namboodiri Brahmin of Kerala, written in Kollam 825 (1649 AD) in a place called Edakad near Talasseri. It appears that at that time our author had an opponent by name Easwara Deekshitar living in Chola country.
Another great disciple of the author was Mochhattiloyit, a well-known personality in Kerala in those days. Kerala Varma was also a great astrologer. Kerala Varma's disciple Punnasseri Nambi Neelakanta Sarma wrote a commentary in Sanskrit. The topic of the work, though called Prasna Marga, covers almost the entire range of the subject: Jataka or predictive astrology, muhurtha or electional astrology, parihara or remedial astrology and nimittas or the science of omens. Here we have, essentially a work that touches some of the most important aspects of life — longevity, death, disease etc. The value of the work is unmistakable. It not only endorses the ancient principles of astrology but also extends beyond by giving methods which are not to be found even in such celebrated books as Brihat Jataka.
Though Punnasseri Neelakanta Sharma's Sanskrit text has been generally followed a manuscript traced at the Oriental Library, Madras, has also been made use of. Some verses in the former have been omitted and some in the latter included.
As earlier indicated the author of Prasna Marga appears to have been a scholar of 13 exceptional merits not only in different aspects of astrology proper but also in such collateral subjects as omens and mantra sastra. Diagnosing from the horoscope the nature of disease and the "spirits" responsible, and prescription of remedies are an important aspect of Prasna Marga.
Today some "men of science" may smile at the author's tracing different types of insanity to "possession" by evil spirits. To rid the world of mental illness is surely the most ancient aspiration. In this our author is not alone. Some of the western thinkers have started believing in ghosts, possession etc., as causing abnormal behaviour as the various therapies employed by neuro surgeons cannot be the answer to a fight against insanity. It is on record that many persons suffering from such mental troubles (some of them seemingly incurable) have been helped by mantra sastra.
According to ancient thought, whatever be the modern jargon-schizophrenia, catatonia, dissociation, paranoia, reactive and endogenous depression, melancholia, maniac depressive psychosis — insanity is caused not only by organic factors but also by 'spirits' or disincarnate beings. All the modern medical magic has not been found enough to cure insanity. Hence the ancient teachings cannot be ignored as out of date.