He was born to a Goddess who came from another world. The entire world revered and feared Kaguya, so people were clearly wary of him and Hamura. He and his brother stood as if above the whole world from birth.
Kaguya ruled alone with her power and seems to have caused a lot of trouble.They had to seal their own mother for the sake of peace.
After that, Hamura and their entire Ootsutsuki clan flew to the moon. Hagoromo was left alone in the world.A world that has not yet recovered from the reign of Kaguya. People who survived the Endless Tsukuyomi. People who found a patron and lost him. People in one moment were left without everything. And it was up to Hagoromo alone to deal with it.
And he did it. He created a Ninshu, thanks to which (as he thought) the situation with Kaguya would not happen again,because people would use their inner forces to connect with each other. Utopia.
He married a human. Someone has accepted him for what he is. She died, but bore him two sons.
They were different, but they loved each other and their father. But utopia is still a long way off-things don't always go the way we want them to.
Ashura was weak,but with the support of others, he gained strength. Then he thought that with love you can achieve everything. Hagoromo liked the idea. Especially if you combine it with Ninshu...
and he decided to make Ashura the heir of Ninshu.
And that was the beginning.
For several hundred years, Hagoromo,a relic of the past, watched the war of his sons, which turned into a war of their clans, and then into an all-out war and the creation of the ninja world. He watched the collapse of Ningshu and the world.
During this time, he clearly drew conclusions. He had learned his lesson. He told Naruto that:
-He was too naive
-It is his fault that he entrusted everything to Ashura,that is, that he left everything in one hand and deprived Indra of it."
-Indra's methods are more applicable now
Despite the risk, he shared his power with Sasuke as well. Because he'd learned his lesson.
Hagoromo created the world from scratch and accidentally destroyed it himself, but he learned his lesson and helped create it again. One. A lone spirit, a relic of the past, the son of an alien Goddess, a God standing over the world...not a very good son and not a very good father.
Hagoromo’s fear of his mother Kaguya is important to behold if you want to understand him. It had a profound influence on his belief and therefore ninshu, the “Will of Fire”, Konoha and the shinobi society.
Hagoromo has the belief that one person alone shouldn’t have much more power than any other person because it leads to that person having great hubris and people fearing the existence of such a great power. The accumulation of power into one person at some point drives the person mad according to his views, which he has because of his experience with his mother.
Hagoromo formed his world-view on this fear. The core of ninshu is using chakra so that people connect with each other. It can foster understanding, but Hagoromo focuses on “cooperation” in order to be stronger / more powerful. The desire to understand others seems to get lost in the struggle for power. It’s just that he wants the power to be a joint effort.
That likely has its roots in how he and his brother Hamura cooperated to seal the ten-tails and how Ashura got stronger thanks to the cooperation of his followers. It gave him the idea to seperate the ten-tails into seperate entities. And the tailed beasts (bijus) cooperated with him afterwards.
The way he talks about Ashura having the cooperation of his followers already shows another problematic view (see The “Will of Fire” part 2: The origin of Konoha’s nepotism for more), which is even more apparent when he talks about the tailed beasts.
Hagoromo: “I divided up the power of the ten-tails that was inside me. And gave names to its parts.”
Ashura is the one in control. His followers cooperate for his sake and it’s implied that Ashura cared for his followers only because they followed him and because he got stronger thanks to them.
Hagoromo also uses the tailed beasts in this way and gave them like objects as inheritance to Ashura and later to Naruto. Ashura’s followers and the tailed beasts aren’t shown to have any problem to cooperate in favor of Ashura or Naruto (or Hagoromo), but Indra’s example shows that the subordination is expected and taken for granted.
That leads the way for the lack of freedom and general oppression in the name of “cooperation” and “love”, which is especially prevelant in Konoha through the “Will of Fire”.
For further emphasis:
Hagoromo thinks eating the chakra fruit, which resulted in Kaguya having more power, was the reason for her change or rather for the people’s view of her to change.
It’s strange how Hagoromo says that the people once looked to Kaguya “like a warm and caring goddess” only to say some panels later that Kaguya didn’t know something of love (in relation to Sasuke and Naruto). Could it be because he doubts the view of the people? But then he wouldn’t think that she changed for the worse. This really shows how being warm and caring doesn’t mean love to Hagoromo. He views “cooperation” as love.
General definition of ninjas: people trained in ancient Japanese martial arts and employed especially for espionage and assassinations
General definition of ninjas in Narutoverse: people who use chakra in order to make jutsus (some more - some less), which are mainly utilized for fights, espionage and assassinations
Hashirama - (Change) to achieve dreams
Ninjas are beings that must make impossible choices in order to achieve their dreams. Whether they have to change in order to accommodate those dreams depends on the nature of their dream. They might have no other choice but to change if they want to achieve their dreams.
Jiraiya - Dream: achieving peace, but how?
Jiraiya: “This world is filled with war... Hatred is everywhere.”
"I think about how to change that...”
“I wonder what peace is... I want to know the answer...“
Jiraiya would like for there to be peace, but he doesn’t know what to change in order to achieve that and what peace would look like.
All ninjas who want peace seem to struggle with that [examples]. And that isn’t surprising considering how the foundation of being a ninja has been violence and war for a long time.
Jiraiya: “He was the first to divine the true meaning of chakra, and he tried to lead the world to peace. They say he travelled the world spreading his religion.”
“Time passed and eventually that religion became our ninja techniques.”
“Being a ninja was not about war, but about bringing peace.“
“The priest was called the Sage of the Six Realms. They called him the Messiah. ... to provide peace and order. ...“
“He must have believed the day would come when people would truly understand one another.“
Jiraiya talks about how the true meaning of chakra got lost when the ninja religion (peace and order) changed to ninja techniques (war). Being a ninja was supposed to be about bringing peace by understanding one another.
Hagoromo - Ninshu and (nin)jutsu
Kaguya was allegedly the first person on “their land” to use jutsus. She ruled by fear to the point that she was called the rabbit goddess or the demon.
Hagoromo, one of her sons, chose a different path. He became the creator of peace, law and order. (This doesn’t mean that his brother chose Kaguya’s path.)
However, what exactly peace, law and order meant back then in regard to culture, ethics and morals is questionable because of all the huge changes with the passage of time. The meaning of them fell into oblivion.
Adding to that, definitions are ambiguous because of different cultures, ethics and morals even without factoring in changes due to time.
There has to be mutual comprehension of each others values and selves in order to understand what someone else means.
Hagoromo founded ninshu, which means ninja religion / teachings and he became known as the Sage of the Six Paths / Realms when he spread the religion as a priest.
Ninshu differs from ninjutsu in the way chakra is used. It was created to inspire hope by taking into account how chakra makes it possible for people to connect to one another in an intuitive and profound way. [see the end of the post for a short explanation from Sasuke] This should lead to mutual comprehension of their values and themselves. As a consequence it should be easier to create bonds of “cooperation”.
On the other hand, ninjutsu was made to create war. Jutsus tend to be violent and even the ninjutsus which aren’t inherently violent (for ex. the Nara clan’s Shadow Jutsus and even medical ninjutsus) are [within this story] only used in and after ninja battles and also while training for ninja battles.
Hagoromo’s children, Indra and Ashura, ended up fighting each other with ninjutsu. Both of them chose ninjutsu over ninshu and passed this (mindset) on to others. Ninjas used predominantly or even only ninjutsu and over time ninshuu ended up being mostly forgotten with only remnants being passed on.
Shinobi society chose to use chakra as a weapon for war instead of using it to understand one another for peace.
Even the remnant of how to use chakra in order to connect with one another in an intuitive and profound way is now practiced with ninjutsu. *Because why would people connect their chakras in a peaceful way to understand one another, when they can beat each other up.*
Sasuke: “If both you and your opponent are first-class ninjas, you can only read inside each other’s minds when your fists meet. There is no need for words.” *only?...*
[Where / From whom did Sasuke learn this anyway? Who knows...]
Conclusion
Ninjas use chakra in the form of jutsus (ninjutsu, genjutsu, ...) for war.
However, chakra can be used in a different way according to ninshuu for peace by connecting with each other.
For ex. medical ninjutsu could be used to help the general population with their illnesses, etc..
One major way of connecting with each other is the connection of minds (thoughts and feelings) and thus knowing one another.
This doesn’t seem to be enough in order to truly understand one another though. First of all, mutual comprehension of each others values and selves is only reached when the people trying to understand one another know themselves first. *And that’s harder than many think.*
Regardless, it's a path in the right direction.
Ninjas are in general people who use chakra.
The Sage of the Six Paths was the one who spread the knowledge how chakra can be used and he apparently emphasized peaceful methods of using chakra. Although he did train his sons in combat when they were young and he did extremely exalt one over the other and who knows what else.
Ninjas ended up having a bloody lifestyle full of conflict and war. However, that isn’t set in stone. Time moves on and things can change. They could change their lifestyle to a more peaceful and supportive one, which would mean that society and individuals could make significant progress towards a better world.
Of course this would require a(n almost) complete revision of the Shinobi system and the mindsets of ninjas. So who knows whether that will ever come to be. Only time can tell [and maybe the author of the manga]...
One of the main disadvantages of the Path of Love is that it is very difficult to adhere to it. Even Ashura's reincarnations failed. Only Ashura and Naruto did not abandon their ideology. But they have one difference.
Ashura is the son of God. He's clumsy,but Hagoromo was respected,so it was unlikely that he had any problems finding friends and communicating. He had many friends,many followers, and so he decided that this was the way to achieve everything.
Naruto had a completely different story - he was an unwanted outcast, so he began to greatly appreciate every connection. Let's clarify: Naruto would have initially followed the Path of Ashura anyway,but in the end he could have turned away from it. But thanks to the psychological trauma, this did not happen. We can say that Ashura is morally stronger than everyone else in "Naruto", because he did not give up his Path,without having psychological injuries.
But their knowledge and skills are also different.
Hagoromo literally said that Naruto is the stupidest of all reincarnations. Naruto said that he himself,unlike Ashura, still does not understand much. Naruto is an outsider teenager who has problems with socialization. He just wants ramen and Sasuke,and everyone he meets tells him to change the world. He wants it, but he doesn't know anything, and he can't do anything. There is only the plot of "working together", beliefs and enthusiasm. And the ability to convince and the qualities of a leader, of course. Ashura originally lived in the family of a God, in the family of a ruler. Of course, he has a different set of knowledge and experience. He probably didn't have much trouble becoming the Heir to Ninshu.