Many astrological predictions come true, quite a mass of them, if one takes all together. But it does not follow that the stars rule our destiny; the stars merely record a destiny that has been already formed, they are a hieroglyph, not a Force,— or if their action constitutes a force, it is a transmitting energy, not an originating Power. Someone is there who has determined or something is there which is Fate, let us say; the stars are only indicators.
The astrologers themselves say that there are two forces, daiva and purus. ¯ artha, fate and individual energy, and the individual energy can modify and even frustrate fate. Moreover the stars often indicate several fate-possibilities; for example that one may die in mid-age, but that if that determination can be overcome, one can live to a predictable old age.
Finally, cases are seen in which the predictions of the horoscope fulfil themselves with great accuracy up to a certain age, then apply no more. This often happens when the subject turns away from the ordinary to the spiritual life.
Ref: Letters on Yoga — I