In the previous contest of the Gambling Match the conditions of the game were (1) that the proof on each side was limited to the evidence of the senses; and (2) that the idea of God was to be excluded from Prakrti as well as all Action. In this debate the first condition must still hold good; but the Kauravas have given up the second themselves; for they have accepted the position of Vaisesika which, even as the higher limit of Nyaya, gives a substantial place to Purusha as a Creator, though still less than that of Prakrti. But they demand proof from the Pandavas in respect of their idea of Yoga and Vedanta. Thus, the question is, Is God the chief Actor in the universe? And conversely, as the individual soul is akin to the Supreme Purusha, must all actions be performed, irrespective of their result, so long as they are performed as a sacrifice? In other words, is all Action imperatively necessary? And so the battle this time is to be fought in Kurukshetra, "the field where Action is deemed imperatively necessary".
Bhishma Parva: The contending parties are gathered on either side; but before the battle begins their whole position and different points of view are examined afresh; and this gives us the Bhagavad Gita, the Song of Krshna, the Supreme Lord of the universe.
Bhagavad Gita in the Mahabharata: The Bhagavad Gita occupies a unique place in the story of the Mahabharata. Its sublime character and wonderful range of thought are universally acknowledged; and so different does it appear to be from the main story of the Epic, that there are many who believe that it is an interpolation. But the Bhagavad Gita is an epitome of the whole Mahabharata, and explains the idea of the parent work in a most remarkable manner. We have observed that the battle of Kurukshetra is a mighty contest of great systems of thought from Sankhya to Vedanta about the question of the existence of God and the necessity of Action; and the idea of the Bhagavad Gita is the same. The Song of the Lord is a brief survey of all systems of Hindu philosophy in connection with the idea of God and the necessity of Action; and so it is told on the field of Kurukshetra, in the midst of contending armies, gathered for the fight. Even a most casual reading of the Gita will show that this is its great theme, considered from different points of view; and its final end is Vedanta, with Krshna as Supreme Purusha, the universal Creator and Actor in one, for whose sake and in whose name must all Action be performed as a sacrifice, and in whom will everything be merged in the end.
Eighteen Chapters of the Gita: The Bhagavad Gita consists of 18 Chapters, and the number of the main Parvas or Sections of the Mahabharata is the same. Such is also the number of the Aksouhinis or divisions of the armies of the combatants, as well as the number of the days of the battle of Kurukshetra. We have seen that this number consists of 7, 6, and 5, and refers to the corresponding systems of thought; Yoga, Vaisesika, and Nyaya; and so the Mahabharata is a great battle between contending systems of philosophy. The idea of the Bhagavad Gita is the same; and, while it retains its own peculiar unity of thought, each of its Chapters has a bearing on the corresponding Parva of the parent work, or the events of the corresponding day of the battle of Kurukshetra.
We have observed that the combatants meet on the common ground of Vaisesika, referred to as Dharma; and so the very opening lines of the Gita indicate the essential idea of the contest. "On the field of Dharma, in Kurukshetra, what did my sons and Pandavas, eager for the fight?" Ask Dhritarashtra of Sanjaya, who describes the great scene of battle to the blind old King. The great field relates to Dharma or the Vaisesika system, where the combatants meet; and the subject of their debate relates to Kurukshetra or the Field of Action. Thus Action, examined from different points of view, is the subject matter of the Gita, and it is this that the King, who represents Nyaya himself, desires to know. The First Chapter of the Gita has a further bearing on the Adi or the First Parva of the Mahabharata; and both describe the array of forces on either side. The Second Chapter, called Sankhya-Yoga, corresponds to the Second or Sabha Parva of the parent work; and we have seen that the Sabha or the Assembly-Hall is really a picture of Nyaya, also called Sankhya-Yoga; and the Gambling Match between Yudhisthira and Sakuni relates to the same idea. In this manner a close study of the Bhagavad Gita will show that it is an epitome of the Mahabharata, as wonderful as the Mahabharata itself.
Fight with Bhishma: We have observed that the battle of Kurukshetra is between Yoga, the first manifest form of Vedanta, on the one hand, and Vaisesika and Nyaya combined on the other; and the first to enter the field against the Pandavas (Man) is the grandsire Bhishma. He is the Purusha of Nyaya; and, as Nyaya is represented by the number 10, he fights for ten days. But Nyaya is only an extension of Sankhya; and the two can be defeated only when it can be proved that Prakrti is created by Purusha himself, and that the manifest world is Purushic in character. In other words, Bhishma can be "slain" only when a Woman, personifying Prakrti, can be transformed into a Man, personifying Purusha. If this is done, Bhishma cannot help being convinced, and would be unable to argue or fight any more and this is actually what is said to have happened in the course of the fight with Bhishma. Sikhandin, born as a girl, has been transformed into a man by means of fasting and Tapas (meditation and austerities); and Bhishma gives up the fight when he sees Sikhandin before him. He lays down his arms, and Arjuna, coming from behind, vanquishes him.
Drona Parva: The place of Bhishma is taken by Drona in the fight. He represents Heart-energy as Water or a Fluid; and believes that it is analogous to the Mind and Prakrtic in character. As his Vaisesika is only a continuation of Nyaya and Sankhya, he has to maintain that the end of life is Knowledge and not Action. Hence, according to him, the Mind is associated with the senses of knowledge rather than those of action; so that the end of life is Knowledge and not Action. But there is an obvious flaw in his position. He cannot hold that the Mind has nothing to do with the senses of action, for the Mind is really associated with both the senses of knowledge and action; but if he persists in his opinion, he will have destroyed the very idea of the Mind, or his own son, Asvatthaman, who represents the Mind. Thus he is on the horns of a dilemma: If he holds that the Mind is associated with both the senses of knowledge and action, he cannot maintain that the end of life is Knowledge alone and not Action; and so he must be vanquished himself. But if he believes that the Mind is concerned with the senses of knowledge alone, his son must die and so when, consistent with his own Vaisesika point of view, he argues that the Mind is associated only with the senses of knowledge, and so the goal of life is Knowledge and not Action, Yudhisthira tells him that his son, Asvatthaman is dead. But Drona represents Heart-energy as analogous to the Mind; and so, if his son (Mind) is dead, he too must die. But Asvatthaman really cannot be slain, for he represents the correct idea of the Mind, as associated with both the senses of knowledge and action; whereas Drona would have been vanquished in any case. For, if he holds that the Mind is associated with both the senses of knowledge and action, he is defeated, but his son lives; and if he believes that the Mind is concerned with the senses of knowledge alone, his son must die. But as, according to him, Heart energy is analogous to the Mind, he too dies after his son. Drona, holding that the end of life is Knowledge and not Action, argues in support of the idea that the Mind is associated with the senses of knowledge alone; and, as there are five senses of knowledge, he fights for five days. As a result of his defective position, Yudhisthira tells him that his son is dead; and hearing this, Drona suffers himself to be slain.