The five vows of ahimsa, satya, achaurya, brahmacharya, aparigra, are the very base, the foundation. They have to be understood as deeply as possible because there is a possibility to move without fulfilling these five steps which constitute the first step of yam.
You can find yogis and fakirs all over the world who have moved without fulfilling these five steps of the first step. Then they become powerful, but their power is violent. Then they are very, very powerful, but their power is not spiritual. Then they become sort of black magicians; they can harm others. Power is dangerous; it can help, it can harm. Not only to others is it dangerous, it is dangerous to the person himself. It can destroy you; it can give you a rebirth. It depends. These five vows are just a guarantee so that the power which arises out of discipline is not misused.
You can see so-called "yogis" displaying their power. That is impossible for a yogi, because if the yogi has really fulfilled these five vows he will no longer be an exhibitionist; he cannot display. He can no longer try to play with miracles -- that is not possible for him. Miracles happen around him, but he is not the doer.
These five vows kill your ego completely. Either the ego can exist or these five vows can be fulfilled. Both are not possible. And before you enter into the world of power -- and yoga is a world of power, infinite power -- it is very, very necessarily needed that you drop the ego outside the temple. If the ego is with you there is every possibility that the power is going to be misused. Then the whole effort becomes futile, a mockery, in fact ridiculous. These five vows are to purify you, to make you a vehicle for the power to descend and for the power to become a beneficial influence, a blessing to others.
They are a must. No one should bypass them. You can bypass. In fact to bypass them is easier than to go through them because they are difficult, but then your building will be without a foundation. It is going to fall any day, collapse any day. It may kill neighbors; it may kill you yourself. This is the first thing to be understood.
The Alpha & The Omega: The Yoga Sutras of Patanjali, Vol 5, Chapter 5:
http://oshofragrance.org/db/books/files/Yoga%20-%20The%20Alpha%20and%20the%20Omega,%20Vol%205.pdf