Exploring sutra 41 Sattvasuddhi, breaks down as follows: One gains purity and cheerfulness of the mind when one is able to master the senses for self-realization. Essentially, you must understand the body, then the heart is purified. When the heart is pure, you are always happy. Concentration of the mind comes automatically without even trying. Only an impure mind is chaotic, forcing you to bring it back again to a state of peace. All the senses can be controlled, and then self-realization can occur. One must understand the first niyama, purity. When one is pure in thought and word, peace of mind automatically occurs. It is rather simple, yet the ego never wants to accept things easily. Try for just one day to be absolutely pure and honest. According to Patanjali you will be tempted to repeat the experiment again and again.
Mary Jane - Feng Shui Yoga Girl - www.fengshuiyoganj.com