Spiritual comes from the word, 'spirit', which meant 'wind', referring to one's breath, 'wind of life', as it were.. there is a sense of it when the phrase 'he/she has spirit' or 'the horse is spirited', meaning there is much life in the individual, be it human or animal... so, from the beginning, there was a recognition in reality of a non-materialness involved within the fabric of reality... the major error of understanding it came with the notion that there was such a thing as the supernatural, a supposed realm somehow 'outside' reality which 'somehow' affected reality... but since the universe is the sum of that which exists, there can be nothing 'outside the universe', that the notion is a fantasy bourne from the times of primeval ignorance, when there was little understanding of the nature of reality, or how it operated, and virtually no understanding of the self, of the mind, and how it functions... the consequnce of pandering to that fantasy was that there arose the notion, again false because of its non-reality orientation, that the spiritual must, then, pertain to dealing with another 'life', one which must be more desirable than the squaller that abounded among the humans of ancient times... the consequence proved to be a very deadly one, as instead of attention being paid to learning more of its true nature, and the improvement of being human and living in the world, the focus turned to demanding acceptance of the squaller as a normalcy, imposing the most evil notion possible to foister on to the ignorant and innocent - the damning of them for the mere fact that they existed, that they were human and as such should be ashamed of being such... one doesn't even give a cockroache or a dog that distinction, nor rats or snakes... only the hatred of one's fellow humans would produce such an abomination, hatred which sanctified domestication of humans - physically as in slavery, and mentally or spiritually as in slavery as well, instituting the false dichotomy of a mind/body split which had one part supposedly 'warring' against the other, and demanding that the 'mind' part be concerned with matters NOT of the real world, but of some 'realm beyond the grave', where all the desires could then be had that were not to be had in reality... this mis-understanding of what 'spiritual' really means persists yet today, despite the overwhelming evidence that life in reality is and can be most wonderous and not to be despised...