Then Duryodhana, first of all he pointed out the military strength of the opposite side. This is intelligence. One should take calculation of the opposing elements or the enemy’s side. In fighting the first thing is to take estimation of the enemy’s side, how much they are strong, how they have arranged. Then one should calculate how to counteract, how to fight with them, this is intelligence. Without taking any calculation of the other side, if you are not prepared, then how you can become victorious?
This is sane proposal, that is, upayan cintayet prajno apayan ca cintayet.. A prajna, an intelligent man, not only think of the bright side on this business, or this fight, or this any…, so many things we have to deal with. Simply we should not calculate the brighter side. There is darker side also. We should always think, “If there is some thief, if there is some rogue, they cheat us, then what precaution I am going to take?” This is intelligence. If I simply calculate that “In this business I will make so much profit.” In the meantime, somebody comes and cheats me and go away, then… Therefore upayan cintayet prajna apayan ca cintayet. Darker side also should be thought of. That is intelligence. Just like they are doing.
After calculating the darker side—enemy means darker side—they can defeat me at any moment. That is darker side.
– Bhagavad-gita 1.6-7 — London, July 11, 1973