Perfection of Yoga [1972 (first) edition] : A.C. Bhaktivedanta Swami Prabhupada
"For the mind is restless, turbulent, obstinate and very strong, O Krishna, and to subdue it is, it seems to me, more difficult than controlling the wind." (Bg. 6.34)
It is indeed a fact that the mind is always telling us to go here, go there, do this, do that--it is always telling us which way to turn. Thus the sum and substance of the yoga system is to control the agitated mind. In the meditational yoga system the mind is controlled by focusing on the Supersoul--that is the whole purpose of yoga. But Arjuna says that controlling this mind is more difficult than stopping the wind from blowing. One can imagine a man stretching out his arms trying to stop a hurricane. Are we then to assume that what was impossible for Arjuna in a more advanced age is possible for us in this degenerate age? We should not for one moment think that we are in Arjuna's category. We are a thousand times inferior.
Moreover, there is no record of Arjuna's having executed the yoga system at any time. Yet Arjuna was praised by Krishna as the only man worthy of understanding Bhagavad-gita. What was Arjuna's great qualification? Sri Krishna says, "You are My devotee. You are My very dear friend." Despite this qualification, Arjuna refused to execute the meditational yoga system described by Sri Krishna. What then are we to conclude? Are we to despair the mind's ever being controlled? No, it can be controlled, and the process is this Krishna consciousness. The mind must be fixed always in Krishna. Insofar as the mind is absorbed in Krishna, it has attained the perfection of yoga.