The Indian thought and practice encountered by Buddha was based on an idea of human beings as a combination of spiritual and physical elements. They thought that the physical side of man bound the spiritual side, and so their religious practice was aimed at making the physical element weaker in order to free and strengthen the spirit. Thus the practice Buddha found in India emphasized asceticism. But Buddha found when he practiced asceticism that there was no limit to the attempt to purge ourselves physically, and that it made religious practice very idealistic. This kind of war with our body can only end when we die. But according to this Indian thought, we will return to another life, and another life, to repeat the struggle over and over again, without ever attaining perfect enlightenment. And even if you think you can make your physical strength weak enough to free your spiritual power, it will only work as long as you continue your ascetic practice. If you resume your everyday life you will have to strengthen your body, but then you will have to weaken it again to regain your spiritual power. And then you will have to repeat this process over and over again. This may be too great a simplification of the Indian practice encountered by Buddha, and we may laugh at it, but actually some people continue this practice even today. Sometimes without realizing it, this idea of asceticism is in the back of their minds. But practicing in this way will not result in any progress.
Buddha's way was quite different. Buddha was not interested in the elements comprising human beings, nor in metaphysical theories of existence. He was more concerned about how he himself existed in this moment. That was his point.
~Shunryu Suzuki, in Zen Mind, Beginner's Mind