When we drink the four cups, we are supposed to recline. Reclining symbolizes complete relaxation, which manifests relief from tension and anxiety. Reclining is the opposite of erect posture, which demonstrates obedience and submissiveness. Soldiers standing erect symbolize the readiness to obey. Reclining is indicative of disobedience, of a courageous stand, of refusing to take orders, of rejecting the authority of man. 


haggadah Section: -- Cup #2 & Dayenu
Source: Festival of Freedom by Rabbi Joseph B. Soloveitchik