I was once told a story about Mahatma Gandhi by one of his close disciples. Apparently, a palmist went to see Gandhiji in order to read his palm and maybe predict his future. He was informed that he would have to wait since Gandhiji was spinning his charkha. After a couple of hours, the palmist enquired how much longer he would have to wait. Gandhiji informed him, "Until I get sampoorn swarajya (complete freedom)."
Gandhiji never believed in palmists or soothsayers of any sort. He was a great karma yogi who believed in the power of action and work. Yet most of our political leaders - who generally have Gandhiji's photo in their offices - believe in astrologers, palmists, etc.
Why is there such a proliferation of fortune tellers? The internet is full of sites for such services. The main reason is that astrologers, palmists, soothsayers and so on prey upon the fear and insecurities of people, particularly ambitious people. For a soothsayer, the combination of ambition and insecurity is perfect fodder.
Ambition is an emotion which stems basically from insecurity. It is different from the desire to gain knowledge or achieve something for the benefit of mankind.
It is an outcome of an emotional state in which a person wants to achieve something in order to show off to his/her family, peers or to the world.
Very ambitious people are often also insecure people, and as they rise in their profession the stakes become higher. The higher the stakes, the higher is the insecurity and hence the brain seeks reassurance about the future. Soothsayers provide such a support by stressing on fate.
In our ancient scriptures such as the Vedas, Patanjali Yoga Darshan and the Bhagavad Gita, there is hardly any discussion on fate. They are mostly focused on Karma Yoga. In the Yoga Darshan it is clearly written that progress in yoga is only dependent on the hard work of the sadhak or practitioner. The only time Patanjali talks about the future in his Yoga Darshan is when he describes the powers of an advanced yogi who may know the time of his death by doing sanyam on his own thoughts and sanskars (memories).
I think the concepts of astrology, palmistry, fate, etc came as the science of yoga declined. Fate as a concept evolved as a way to suppress questions and inquiry about events and their sequence. Since then there has been a continuous debate about fate and free will.
I believe that what we are and what we will become are controlled by our actions alone. If it is not so then the whole notion of evolution will be negated. Hence we are all endowed with free will and have the power to change our destiny.
Recently, scientists have shown that by our actions we can change our genes and hence our future. The science of epigenetics, as it is called, shows that genes are not only inherited but can also be altered by our behaviour and the environment. This genetic change is more pronounced during our early years and hence the environment of our childhood and formative years plays an important role in what type of human beings we will become. It is not only our experiences but the genetic changes in our childhood that decide our future.
Also, these altered genes can be transferred to our progeny. This is the basis of evolution and it is dependent on our actions. Maybe our ancient rishis or yogis had an inkling about this process and hence stressed early education through gurukuls. The same could also be the basis of the sanskars that Patanjali talks about.
Individually, we have free will and can change the course of our life. But collectively, as people living on planet earth, our evolution is guided by the cosmic forces of the sun, moon and the resulting forces of environment. These forces guide the destiny of humankind and not the sayings of soothsayers.