Is it plausible our ego in itself constitutes our liberty? As you say Madfool the ego" realizes its own insignificance". It serves us in order for the physical body to survive in our physical world.Yet often holds us back spiritually, mentally and physically. Perhaps the ego serves us to protect our physical form but when it is allowed to dominate our conscious self our ego can blind our other senses , leading us to believe that it is our true self..Our ego may be necessary in order for us to prolong our lives...but prolonging life at any cost .Perhaps our ego like a horse pulling a cart should be carefully controlled. At least a carefull balance attained and an ability to mute the ego's voice is perhaps advantageous..While not being the true self, perhaps the ego is a real construct..How to control the ego may be among our intrinsic goals as humans.