The name Drona comes from the Sanskrit root dru “to melt”. Therefore, Drona implies “that which remains in a melted state”.
A thought or physical act once performed does not cease to be, but remains in the consciousness in a more subtle or “melted” form as an impression of that gross expression of thought or action. These impressions are called samskaras. They create strong inner urges, tendencies, or propensities that influence the intelligence to repeat those thoughts and actions.
Oft-repeated, such impulses become compelling habits. Thus, we may simplify the translation of samskara in this context as inner tendency or urge, or habit. The preceptor Drona symbolizes samskara, broadly defined as inner tendency or habit.
According to the historical story in the Mahabharata, Drona was the masterly preceptor who had taught archery to both the Kurus and the Pandavas. During the battle between the two parties, however, Drona sided with the Kurus.
The good discriminative tendencies of the soul’s pure intelligence (buddhi) and the wicked mental tendencies of the sense mind (manas) had both learned from Inner Tendency, Drona, the battle arts of wielding, respectively, the weapons of soul-revealing wisdom, and of truth-obscuring sense consciousness.
The subconscious urges of one’s samskaras, if good, help to create present good thoughts, actions, and habits. When these innate urges are evil, they rouse wicked thoughts that turn into evil actions and habits. Just as a bird turns its head to focus one eye at a time on a given object, so Drona, the samskara– or habit-guided intelligence, uses one-sided vision and supports the dominant tendencies.
Thus Drona, the inner urge, joins the wicked mental tendencies (Kurus) when they are predominant in a man. Therefore, unless samskara, or the sense-habit inclination, is purified by wisdom, it will be found to be a follower of Duryodhana, or King Material Desire. This is why, in the devotee who has yet to win the victory in the battle of Kurukshetra, Drona or the bad-habit-influenced intelligence joins the side of the Kurus or the wicked mental tendencies, helping them to direct their arrows of piercing evil against the discriminative powers.
Excerpt from God Talks With Arjuna: The Bhagavad Gita
Note: The Bhagavad Gita is not, as is commonly supposed, a record of the events that happened during the battle of Kurukshetra. This part of the epic poem Mahabharata is an analogy. Its purpose is to guide, equip and mentor a seeker of God-consciousness. It seeks to familiarize the seeker with his inner domain, his bodily kingdom. It introduces him to the enemy and to the vast armies who stand in his support. Finally, it introduces him to his own Kurukshetra- his spiritual battleground- where he will fight (and win) the war against those forces within him which cause him to forget his relationship with the Supreme.