Astrology is a Vedic art. The Vedas explain that the destiny of human beings is determined by the stars. A person takes birth under a particular conjunction of planets and stars, which is represented in his birth chart, and by following the calculations given in the sastras an expert astrologer is capable of making accurate predictions about his life. Different celestial bodies influence an individual in different ways, just like ropes pulling a puppet. The position of different celestial bodies is going to influence what kind of family one will take his birth into, what education he will receive, what kind of spouse he will have, what challenges he will face during his life, when and where he will die, and even influence how he is going to think!
These influences act according to one’s karma. The planets and stars are actually not the cause, but an indication of how karma is acting over an individual. The purpose of such a science is to help one understand where he is in the wheel of samsara and thus be able to find his way to a progressive life.
Naturally, nowadays astrologers are normally not so learned. At best, a modern astrologer can predict general tendencies to one’s life, favorable and unfavorable periods, calculate compatibility between couples, and so on, but there are stories of how astrologers of bygone ages would be capable of discovering the color of a pencil that one is holding in his hand, or how many coins there are in his pocket, just by astrological calculations. When Sanatana Goswami escaped the prison and was traveling with a servant, an astrologer was capable of predicting that the servant was keeping eight gold coins, a piece of information that led to a failed plot against their lives.
If an astrologer can predict such things based on the position of the planets and stars, it means that our destiny is fixed up to the smallest details. This idea appears to conflict with the concept of free will. If everything is fixed, to such an extent, it seems that there is very little space for our free will. This can easily lead to a conformist mentality. If everything is fixed, why should we struggle to make any kind of advancement?
The answer is that our karma works like an airline. As soon as one enters a plane, he is committed to staying until the destination is reached. It’s not possible to jump half-way. If we take a plane from Delhi to Paris, for example, we are going to be forced to stay on-board until it reaches Paris, no matter how much we may regret it. The airline has various flights going to different routes, and one can choose which one to take, but once the choice is made, one is forced to stay until the plane reach its destination.
However, there are still two opportunities to exert our free will: one can decide how to spend his time during the flight and can choose where to go next. He can pick up a fight with someone, or try to hijack the plane, and create a situation where he will be arrested as soon as the plane touch the ground, or may make friendship with some rich person and get a nice job, or still, may use the time on some spiritual activity and get an eternal benefit. This part is up to us to decide.
In other words, our past karma determines the situation we are in now, and it also limits the choices we have in the present moment, but still, some choice is available, and if we make the right decisions, we can improve our situation. If, on the other hand, we make the wrong choices, we may regret them later.
Therefore, we should be careful with what we desire, because what we desire is going to determine our actions, which in turn are going to determine our next destination. Desire leads to action, and action creates new karma that forces us to go through certain circumstances in the future.
Another point is that, as promised in the Bhagavad-Gita, if one surrenders to Krsna he is protected from his past karma. Under this supreme protection, one has the opportunity of having a clean start, being able to pursue spiritual life with much more freedom than it would be normally allowed by his past karma. One may be destined to be a poor uneducated laborer, but end-up becoming a learned sannyasi, for example.
There are two caveats, however: one is that Krsna protects one from his previous karma to the degree he surrenders unto Him, therefore it really works only for really sincere persons. If one surrenders only 10%, he is still 90% under his past karma. The second is that if one decides to give-up spiritual life and go back to his past material pursuits, trying to forget Krsna, he will just go back to his past karma. The spiritual advancement is never lost of course, and Krsna will do everything to get him back, but in terms of material achievements, he will probably not get more than he was initially entitled.
There was, for example, the story of a sannyasi that left and became a taxi driver. As a sannyasi, he had a position of leadership inside our movement, was very well respected, and had all material facilities. After he left, however, he just went back to his past karma, becoming a humble taxi driver.
In the case of materialistic persons, however, free will is very much restricted, because not only the material situation but also the consciousness is determined by past karma. What he is doing now is determined by his past activities and desires, and because he is not actively trying to change his consciousness and his desires, his next actions are going to follow the same line, leading to a continuation of the same situation. Basically, his fate is already determined. Unless he meets a devotee, there is little hope for some real chance in his life. That’s why it’s so important for us to try to actively spread Krsna Consciousness: we need to at least give people an opportunity.