The killer instinct, the temper, the fury
It does get results, but there is something higher. One of the analogies that is given is the yacht. Many people think that the yacht can go fastest when the wind is directly behind, blowing forward. But the yacht can go faster if it is across the wind. The mechanical principle involved is different – the inclined plane – and the yacht can go faster than the wind. Most people find this incredible, but it can be looked up and verified. (There has to be a keel to hold the boat steady.)
This example is given in Zen. The passions are not direcdy opposed, but they are crossed and so made use of in a spiritual way. The heart doesn’t run directly before the passions. It runs across them.