INTRODUCTION TO THE BHAGAVAD GITA AS IT IS
by A.C. Bhaktivedanta Swami
The  Bhagavad-gita  is also known as  Gitopanisad . It is the essence of Vedic knowledge and one of the most important  Upanisads  in Vedic literature.
There are many commentaries on the  Bhagavad-Gita  in English, and the necessity for another edition should be explained on the following basis: an American lady asked me to recommend an English edition of the  Bhagavad-gita  which she could read. I was unable to do so in good conscience. Of course, there are many translations, but of those I have seen—not only in America, but also in India—none can be said to be authoritative, because in almost every one of them, the author has expressed his personal opinion through the commentaries, without touching the spirit of  Bhagavad-gita  1  as it is.
The spirit of  Bhagavad-gita  is mentioned in the  gita  itself. It is like this: if we want to take a particular medicine, then we have to follow the directions written on the label of the bottle. We cannot take the medicine according to our own directions, or the directions of a friend not in knowledge of this medicine. We must follow the directions on the label or the directions of our physician. The  Bhagavad-Gita  also should be accepted as it is directed by the speaker himself. The speaker is Lord Sri Krsna. He is mentioned on every page as the Supreme Personality of Godhead, or  Bhagavan .  Bhagavan  sometimes means any powerful person or demigod, but here it means Krsna. This is confirmed by all the great teachers, including Sankara and Sri Caitanya  Mahaprabhu . In India there are many authorities on Vedic knowledge, and they have virtually all accepted Sri Krsna as the Supreme Personality of Godhead. We should therefore accept  Bhagavad-Gita  as it is directed by the Supreme Personality of Godhead Himself.
Now, in the Fourth Chapter, the Lord tells Arjuna that this yoga system of the  Bhagavad-Gita  was first spoken to the Sun-god:
The Blessed Lord said: I instructed this imperishable science of yoga to the Sun-god, Vivasvan, and Vivasvan instructed it to Manu, the father of Mankind, and Manu in turn instructed it to Iksvaku. This supreme science was thus received through the chain of discipline