 Despite his earnest efforts, he never truly grasps military matters until one day walking on the beach he espies a clam and a shrike locked in combat.The shrike's beak has been trapped and it cannot escape; at the same time the clam is vulnerable as it is only safe so long as it holds on.The lesson Watōnai draws from this is "to provoke a quarrel between two adversaries, and then catch both when they least expect it."