This is a very good question, and I feel one that is beyond me to answer, but here are my thoughts anyway--!
Have you ever read anything by Jorge Luis Borges? I am thinking in particular of his short story, 'The Immortal'. In it, there is depicted a group of people (described as dog-like) living in caves and drinking brackish water out in the wilderness. They do not speak, and they appear to be brutish and inferior to the narrator who comes across them. It is revealed later, that these dog-people have achieved immortality by drinking the stagnant, filthy water of the river of life. Over the years of their endless existence, they sample every pleasure, and one by one they are discarded. No finite pleasure, they think, can satisfy their infinite desire. But they have already found what they seek. Contemplation is their great pleasure--the working mind, the translator of stimulus to sensation--is the thinker, the seeker, the spirit perhaps the greatest hedonist of all?
I have seen the Ego as corruption--the ties that bind us to the earthly experience, and by its nature transitory and illusory. In a sense, this notion has the support of science--the brain is a perceptive tool, which picks up signals and interprets them in a way that we have evolved to find meaning in, but the signal itself matters less than the singular interpretations that our minds inflict upon us. We could be 'seeing' anything, or nothing.
What Westerners like myself call 'Eastern' spirituality or philosophy often posits that the Ego is a false division, and I think this is a good way to look at it. If we are all atoms, all no more and no less a part of the universe than a stone, or a tree, or time, or space, then the idea of the I against the It, the self and the other, the spectator watching the game through the eye sockets of its hollow head--this is a misguided conception. For a good number of years now this has been my thinking, but, now, I cannot help but feel that this notion does not go far enough.
The question for me is, can we distinguish between 'earthly' desires and 'spiritual' desires? Is it not enough that we do not accept, whether our unacceptance is corporeal or not?
Feel your heartbeat. The rhythm gives the lie to the mind/body dichotomy, if we would just listen it tells us, 'I am I am I am I am'. What is the Ego but the fantasy of matter? What is the spirit but the fantasy of the Ego? We conflate the concepts of 'selfishness' and 'earthly' with the Ego for good reason, but the spirit quest, the journey to higher truth, the ultimate realisation--nirvana, moksa, enlightenment, heaven, the Elysian fields--is this path not as much chosen selfishly? I cannot speak for others, but my motives are never clear enough to me for me to say, 'In this I am selfless'. There is always this lure of power, of status, of 'I am searching' set against those who we see as not searching.
Our lives, our thoughts, our heart beating, these whisper 'I am', but if we could just listen to those around us, and hear the voice of another, we might hear instead 'we are we are'. But what can mere atoms hear?
We try to escape the Ego, and free ourselves of it, but I have come to believe that we are it, inescapably. This is the thing that is. My spiritual path seems to have stolen my spirit, and I now find myself looking at a new materialism. I've picked the lock on my cell only to find that the guards are imprisoned too--!
I fear that whatever sense I may have made initially has descended into incoherency, and in any case, I am unsure of what exactly I am attempting to say, so I shall leave it there, with one last thought made far more poetically than I could ever manage.
To quote the title of the famous painting, 'Et in Arcadia ego'. Even in Arcadia I am.
Much peace and blessings to you, as ever :)