All true religion finally leads to pure spirituality where there is nothing but Oneness like pure space. Can you divide space? No, because division is mental. Spiritual reality is beyond Time-Space continuum. However, due to ignorance of true spiritual reality, Nepalese people are engaging themselves in cat fights based on caste system of Nepalese society which itself is not in harmony with Vedic Scriptures. Most people who claim themselves to be a Hindu don't even have true knowledge of Vedanta. How many Nepalese people adhere to the Upanishadic words? It clearly declares these four sentences and there is no need to cat-fight on castes which doesn't exist in reality.
1) Tat Tvam Asi : That I am. What is That? That is beyond mind, therefore indescribable.
2) I am Brahma: When Atma infinitely expands then it is called Brahma. Atma envelopes the entire Brahmanda. In Vedic Sanatan Dharma, every single entity is one undivided Brahma.
3) Pragyanam Brahma: Pragya means consciousness in Sanskrit. And this awareness itself is the true Spiritual reality which is Brahma. Existence itself becomes aware of itself. Therefore, Consciousness is Brahma.
4) Ayam Atma Brahma: Atma is the word for the true Self within. This Self is not your ego bound self but is transcendental awareness which is a witness consciousness. This is you. You are this, not the limited ego bound consciousness which thinks I am male or female, Bahun or Chettri etc. etc. Atma is sexless and also caste-less. Your true identity is Atma.

There is no place for caste in Vedic Sanatan Dharma. Varna system has been wrongly manipulated as caste system by birth. Varna System infact came from the 3 qualities of human mind: Rajas, Tamas, and Sattva. Rajasic people are always involved in activites, Tamasic people rest a lot and are slow in understanding things, and Sattvic people are those who are serene, calm and intelligent. In true Yogic culture, all these mental modification do have colors as well. Rajas has red, Tamas has black and Sattva has white. And every single individual has all three present in some degree all the time. The variations of these qualities makes your personality and you behave accordingly. And a Varna System (system based on Rajas, Tamas and Sattva) came into being to categorize people based on their mental modifications. And these mental modifications changes through-out life based on your Karmic predisposition. There is no place for Caste-System based on birth on Vedic Sanatan Dharma.
Therefore, Nepalese people need to understand these 4 Maha-Vakyas and practice true Vedic Sanatan Dharma (Nepalese context who think they are Hindu). 

my question was simple, can u comprehend aatma without using your brain ? since vedic sutra says they are two different things, a person in coma can type to answer too right?. forget that and lets say aatma exist sexless casteless as you said but aatma also has will, desire, activity and character so how can you claim it doesn't have desire to discriminate?. In old time, kings and noblemen divided people into categories that existed in time according to their type of works. since bramin was close word to being brahma some clever aryan sect saw this an opportunity to claim that they reached brahma level , called themselves as brahmin (pundit) and belittle fellow aryans who were doing dirty work to gain richness and empower over them. aatma was a vehicle to establish caste system if not the source eh?

DNA and proteins are nanides like micro robot.robot can not work without power. Blood is refined raw material delivary system.

Food is raw material like ores (iron ore, gold ore, other minerals etc yet to be purified). Food ( ores) are refined inside our body, Like mineral extraction industries . once purified metals are used for different purpose.
Similarly once purified food is used to produce energy, like refined oil. Energy produced from oil and other sources used to fuel robots, drones which perform various tasks.

Energy produced from food is used to fuel nano robots (DNA and proteins) which performs various tasks inside our body. But these nano robots can not work forever. Like machines which gets broken after sometime and can not be used. These nano robots DNA and proteins get broken after sometime because of wear and tear and other problems.they stop working and we call it death.

@Stallon..... Very interesting analogy and quite poetic at times. Enjoyed reading it !

@iLED009.... You have asked some very thoughtful questions!
-- ".....then, how come caste system evolved in this particular society?"
> Caste system is not just prevalent in present Hindu society but also present in Islamic and other societies as well. For exampple, Shia and Sunni Muslims exist in Arab world. There was a time in America when Whites were not allowed to marry Blacks. There were separate water fountains in USA, whites did not touch blacks. In other words, blacks were the untouchables. These are just some examples. There are many more!
Vedas are highly encoded and symbolic in nature. The chances of misunderstanding is higher than understanding. For example, in Purusha Sukta, it is said that 'Brahmano mukhamasit' meaning Brahman came from his mouth. What do you understand from such symbolic encoded verse? Do you take is literally? Or is there encoded message in that? Also, Purusha Sukta says, 'Padbhyagam Shudro Ajaayat, Chandrama manaso jaata,' meaning, 'The Purusha's feet became the Shudra (working class) and Purusha's mind became the moon. What do you understand from such highly encoded verse? Do you take it literally? The Varna System and Caste System by birth are two distinct things. The present caste system by birth has been evolved by misunderstanding of Vedas and also intentionally wrong manipulation of Vedas to satisfy human greed. There is no limit to human greed. If Hitler uses Vedic Swastika symbol, is it Vedas fault?
-- What motivated the need for such hierarchy?
> First of all you need to understand that Varna System and Caste System are not the same. The hierarchy based on caste by birth is not just the result of one thing. For example, in chemistry, one reaction leads to another reaction. The formation of carbon and hydrogen leads to the formation of Methane gas. Similarly, the hierarchy may have been evolved as a result of ignorance of true purport of Vedic text and also accompanied by crooked minds taking the advantage of the situation for short term profit and power. The hierarchy has evolved due to long social chain reaction propelled by ignorance and human greed. If Vedas says, Horse Yagya, you don't bring a horse and sacrifice horse to the Agni deity. But in democracy, two fools can win over one wise person if voting is everything. Such is happening these days, unfortunately.
-- "Why aren't we correcting?"
> If you like cheap items made in china, would you like correcting it and make the life of Chinese people more better? Everybody knows, Chinese people are paid 20 to 30 cents a day, but who cares? Similarly, correcting a social problem like caste system doesn't happen overnight. There are people who are trying to correct it, but we need more good people with true knowledge of Vedas out there. Vedas are in Sanskrit and only handful of people know Sanskrit. The whole education system of Nepal needs to be changed and the government should bring a new holistic education system with Sanskrit as compulsory subject.
-- "Is there a disconnect with Vedic facts and practice.?
> Yes, there is. Gadhimai mela kills thousands of buffalo. Such activities is not prescribed by Vedas. The Brihadaranyaka Upanishads declares that, "You don't have right to interfere with the life of even an ant." The moment you get all the knowledge from the Upanishads, you strictly become a vegetarian. You cannot love an animal at the same time wanting meat from that animal to satisfy the taste buds.
-- "Why do we have caste system even though our Vedic scripts doesn't state such?
> Do you blame science for Hiroshima and Nagasaki bombing? Do you blame airplanes for 9/11 attack? Do you blame guns for gun-violence in America? Stupidity is the result of ignorance of totality and its connections with its parts. If people don't understand why something is existing as it is, then their behavior will not be in coherence with natural law. When you understand natural law, you start co-operating with it.

@Khaobadi.... I recommend you move beyond stardust and space. There is no doubt about the importance of star dust. But, when you start asking question like, "What is space and why it exist at all," then you move beyond quantum physics. Where quantum physics ends, Vedas starts.

@controversial.... The word 'comprehension' is inapplicable to Atma. Atma is the seer and seer cannot be seen. Can your eyes see your own eyes? Your pure and higher intellect will be able to help you reach towards the Atma but Atma has to be realized. The more cleaner the mirror is, the better it can reflect the objective world. Similarly, purer the intellect, more will be the reflection of Atma.

@UJL   

It is understandable that you are getting into metaphysics with questions like, "What is space and why it exist at all ?" and so forth. In other words, you seem to be asking why the universe is so fine tuned making it possible for everything in it to exist. Why is gravity so weak in comparison to other fundamental physical forces of the universe and so forth. It is likely you would not be satisfied with possible answers presented from the point of view of just physics.

Having said that, some theoretical physicists have tried to answer "Why universe as we know it exist at all ?" I would encourage you to look into the anthropic principle. When some of these theoretical physicists attempted to answer this question with their theories, they were resoundingly criticized by their peers in the science community for jumping outside of science or "falling off the wagon." In other words they were accused of cooking unscientific explanations and getting into metaphysics.

Besides contention in the realm of Quantum Mechanics and Astrophysics, many studies in Neuroscience too have attempted explaining this phenomena. Here, I am going to regurgitate Dan Dennett. Any time someone talks about aatma, consciousness, et al, I like to do this, although it is a futile attempt. And whenever I do this, I feel the same cringe you and I had watching the famous scene at Bow and Arrow pub (used to be at Mass Ave) in Good Will Hunting where Will splendidly says one of the noted lines Matt Damon has ever spoken on screen, “You got that from Vickers, 'Work in Essex County,' page 98, right? Yeah, I read that too. Were you gonna plagiarize the whole thing for us? Do you have any thoughts of your own on this matter?” (1). That's why citing books and philosophers alluding to my point makes me feel the same way character Clark would've felt (although, I don't have a degree).

OK, so Dan says, “The idea that you could somehow boil mind, the spirit, down to brain activity is just deeply repugnant to many people. People want their minds to be beyond all measures. The idea that their minds are boringly finite is not attractive. And so people want to believe that there is more and more and more in their mind than any science can ever tell them. One of the problems of explaining consciousness is that people think they are conscious of lot more than they actually are conscious of. So one of the first thing that you have to do before doing a good theory of consciousness is you have to beat consciousness back down to size. You have to get a proper account of what the phenomenon is.

He continues, “One of my favorite artifacts is the British Seagull outboard motor which is dead simple and their motto is 'what isn't there can't break', much the same could be said about consciousness. What isn't there doesn't have to be explained. It's just not there” (2).

He argues that the very chutzpa of somebody thinking that one can explain consciousness is just out of the question. He provides an analogy of making a rational argument, say on consciousness, where the contention is to have a conclusion so powerful that it knocks out the opponent. But in fact that doesn't change people's mind at all. Its very hard to change peoples mind about something like consciousness. And the reason for that is that everybody is an expert on consciousness. On every other fields of study you might have a strongly held opinion, say on vaccination or climate change, but you don't consider yourself an expert. Unfortunately when it comes to consciousness, you're an expert (3).

Science of brain is an evolving field. All this assumptions, tirade, claims and counter claims behind arguments on aatma and consciousness would make more sense if discussed on the premise of science. A similar pointer made by Prof Susan Greenfield where she concedes that we should assume that any 'scientific' explanation of consciousness must also include its quintessential feature: subjectivity (4).

Bottom line, it seems 'consciousness' is a swampland for scientific argument where threaders and trolls can agree to disagree.

The word 'comprehension' is inapplicable to Atma. Atma is the seer and seer cannot be seen.