Bhagavad Gita (Chapter IV-7)
"Whenever there is decay of righteousness O! Bharatha And a rise of unrighteousness then I manifest Myself!"
This sholaka form Bhagvad Gita answers the question why a war was essential; it was done to re-establish the Dharma and to teach the generations to come that whenever there is rise of Adharma, establishment of Dharma would be done by the Lord himself or by his messengers.
At the beginning of the Mahabharata, there's an anecdote on how mother earth comes to Vishnu, to request Him to reduce her burden. Similarly, the rishis ask Him to save them from Kamsa. And Vishnu decides to take a poornaavatara. He descends to Teach and Establish Dharma and Fight and Destroy Adharma.
I applied similar logic when discussing Shakespeare's play Hamlet with my son, and in the process, I discovered the major character behind the entire play, who only has a small role in the play itself!
Shakespeare's plays have enduring appeal because they speak to people in a highly personalised way. They are ambiguous and nuanced, and they lend themselves to alternative interpretations depending on the reader's point of view. Indeed, the same person revisiting a Shakespearean play many years later would get a different message from it.
This was indeed my experience. I had first read Hamlet long ago in my youth, and when I discussed it today, I found I was thinking about it very differently. When I was much younger, I took the entire play at face value and thought I had been able to appreciate it for what it was. I couldn't have been more wrong. Today, I realised that I had changed enormously as a person since I last approached the play, and consequently, it seemed a completely different story. The big change in my life has been my move away from being a religious believer to being an atheist or a rationalist. And when I thought of Hamlet today, I realised that the one aspect of the story that stuck out like the proverbial sore thumb was the ghost of the old king.
As a rationalist, I now know that supernatural phenomena like ghosts simply don't exist. So did Shakespeare do nothing more than write a silly ghost story?
Not so fast.
I applied the same logic that Seshadri Kumar did to the Mahabharata. I assumed that the play was literally true, i.e., that the characters all did see and do the things they have been depicted as seeing or doing.
Now, the play became a lot more interesting. If there was no ghost, then who was it that Hamlet, Horatio and the soldiers saw at the beginning of the play? It must have been a flesh-and-blood person, but what was his identity?
To answer that question, we need to ask ourselves what the ghost actually did. And the answer to that question is that the ghost incited Hamlet to kill his uncle in revenge for the murder of his father.
Now why would someone impersonate a dead king to incite the murder of the current one? Well, as the detective at the scene of a murder might ask, who stands to gain from the crime? Who is the beneficiary? And indeed, the answer is clear at the end of the play. It is Fortinbras, prince of Norway, who arrives in Denmark in time to see the ruling family dead and the kingdom ready to fall into his lap.
Who is Fortinbras anyway? He's the son of King Fortinbras of Norway, who was killed by the elder king Hamlet. The younger Fortinbras has been gathering an army to attack Denmark in revenge, but has been restrained by his uncle the current king of Norway.
Now that's very interesting. So Fortinbras wants to attack Denmark under its current king Claudius, avenge his father's death and win territory for his kingdom. He's thwarted by his uncle in his plans to attack Denmark outright, and so he goes on a campaign against Poland instead, for "a little patch of ground that hath no profit in it but the name". The campaign against Poland is therefore just a smokescreen. Although Fortinbras made a vow before his uncle "never more to give the assay of arms" against Claudius, it's clear he intends to achieve his purpose by other means. Denmark is always his primary target.
So, now that we have a suspect and have established a possible motive for his act, let's look at the options one would have in Fortinbras's place, now that direct military action is ruled out. The most obvious route is to look for and exploit schisms within the Danish ruling circle. After sufficient investigation, the murder of the elder king Hamlet by Claudius must have been uncovered, and in the process a potential ally (prince Hamlet) identified. But Hamlet was oblivious of his father's murder and would have to be told. Why would he believe an outrageous story like that? What proof could Fortinbras furnish to Hamlet to convince him of Claudius's guilt? None at all!
That's probably why Fortinbras decided to use the stratagem of impersonating the king's ghost and telling Hamlet the story from the old king's point of view. As a superstitious man (like most people were in that society), Hamlet would not dare ask the ghost for proof. He would accept the story without question. And that is exactly what happened. With the seeds of doubt planted in his mind, Hamlet then set about doing all the things he had to do before the play ended. And once Denmark's ruling family lay dead, Fortinbras mysteriously appeared to claim the Danish throne and avenge his father.
A dark night, a bit of makeup, and an armor that hid everything about a face except for the eyes exposed by a visor - that was all that was needed. (It need not have been Fortinbras himself who impersonated the dead king. It could have been anyone from his entourage who had similar features.) The plan worked brilliantly. Hamlet was so convinced by Fortinbras's story that after some hesitation, he set about planning his revenge. The later scene of the ghost when Hamlet is alone with his mother is probably Hamlet being delusional. His mother can see no ghost. It is entirely in his own imagination, unlike at the beginning of the play, when Horatio, Bernardo and the soldiers can all see the ghostly figure in armour.
And so this is Shakespeare's clever story of Hamlet - a story of how the young prince Fortinbras of Norway avenged his father's death and won a victory over his enemy Denmark by setting the prince of Denmark against his own uncle. The entire play was about how Fortinbras's brilliant plan to conquer Denmark succeeded.
As with Seshadri Kumar's analysis of the Mahabharata, my own analysis of Hamlet from a rationalist point of view led to an answer that should really not be surprising in hindsight.