Suppose I am asked: “Can I become a great mathematician?” What must be my answer? “You must have a natural aptitude and capacity for mathematics to be a great mathematician. If you have not that capacity, you cannot be a great mathematician in this life.” But this does not mean that you cannot learn any mathematics. To be a great mathematician you must be born with a special capacity for mathematics. To be born with such a special capacity means that you have practiced it in very many lives and now you are born with it ready-made. It is the same with Yoga. Every man can learn a little of it. But to be a great Yogi means lives of practice. If these are behind you, you will have been born with the necessary faculties in the present birth. There are three faculties which one must have to obtain success in Yoga. The first is a strong desire. “Desire ardently.” Such a desire is needed to break the strong links of desire which knit you to the outer world. Moreover, without that strong desire you will never go through all the difficulties that bat your way. You must have the conviction that you will ultimately succeed, and the resolution to go on until you do succeed. It must be a desire so ardent and so firmly rooted, that obstacles only make it more keen. To such a man an obstacle is like fuel that you throw on a fire. It burns but the more strongly as it catches hold of it and finds it fuel for the burning. So difficulties and obstacles are but fuel to feed the fire of the yogi’s resolute desire. He only becomes the more firmly fixed, because he finds the difficulties. If you have not this strong desire, its absence shows that you are new to the work, but you can begin to prepare for it in this life. You can create desire by thought; you cannot create desire by desire. Out of the desire nature, the training of the desire nature cannot come.