Out of these five basic subject matters in Bhagavad-gita it is established that the Supreme Godhead, or Krishna, or Brahman, or the supreme controller, or Paramatma — you may use whatever name you like — is the greatest of all. The living beings are in quality like the supreme controller. For instance, the Lord has control over the universal affairs of material nature, as will be explained in the later chapters of Bhagavad-gita. Material nature is not independent. She is acting under the directions of the Supreme Lord. As Lord Krishna says, mayadhyakshena prakritih suyate sa-caracaram: “This material nature is working under My direction.” When we see wonderful things happening in the cosmic nature, we should know that behind this cosmic manifestation there is a controller. Nothing could be manifested without being controlled. It is childish not to consider the controller. For instance, a child may think that an automobile is quite wonderful to be able to run without a horse or other animal pulling it, but a sane man knows the nature of the automobile’s engineering arrangement. He always knows that behind the machinery there is a man, a driver. Similarly, the Supreme Lord is the driver under whose direction everything is working. Now the jivas, or the living entities, have been accepted by the Lord, as we will note in the later chapters, as His parts and parcels. A particle of gold is also gold, a drop of water from the ocean is also salty, and similarly we the living entities, being part and parcel of the supreme controller, isvara, or Bhagavan, Lord Sri Krishna, have all the qualities of the Supreme Lord in minute quantity because we are minute isvaras, subordinate isvaras. We are trying to control nature, as presently we are trying to control space or planets, and this tendency to control is there because it is in Krishna. But although we have a tendency to lord it over material nature, we should know that we are not the supreme controller.
The devotee can constantly think of the object of worship, the Supreme Lord, in any of His features — Narayana, Krishna, Rama, etc. — by chanting Hare Krishna. This practice will purify him, and at the end of his life, due to his constant chanting, he will be transferred to the kingdom of God. Yoga practice is meditation on the Supersoul within; similarly, by chanting Hare Krishna one fixes his mind always on the Supreme Lord. The mind is fickle, and therefore it is necessary to engage the mind by force to think of Krishna. One example often given is that of the caterpillar that thinks of becoming a butterfly and so is transformed into a butterfly in the same life. Similarly, if we constantly think of Krishna, it is certain that at the end of our lives we shall have the same bodily constitution as Krishna
In this verse the word buddhi-yogam is very significant. We may remember that in the Second Chapter the Lord, instructing Arjuna, said that He had spoken to him of many things and that He would instruct him in the way of buddhi-yoga. Now buddhi-yoga is explained. Buddhi-yoga itself is action in Krishna consciousness; that is the highest intelligence. Buddhi means intelligence, and yoga means mystic activities or mystic elevation. When one tries to go back home, back to Godhead, and takes fully to Krishna consciousness in devotional service, his action is called buddhi yoga. In other words, buddhi-yoga is the process by which one gets out of the entanglement of this material world. The ultimate goal of progress is Krishna. People do not know this; therefore the association of devotees and a bona fide spiritual master are important. One should know that the goal is Krishna, and when the goal is assigned, then the path is slowly but progressively traversed, and the ultimate goal is achieved.