Shinobi no mono

Kotaro:
Goemon, what does a ninja live for? [Continues] Starting as a innocent toddler, he must endure hard training in ninjutsu... then he's sent to serve some warlord in the east or some daimyo in the west... and does so knowing that his life is always at risk. If he is captured, he must endure exquisite tortures, and yet not divulge the truth. Rather than disclose his name, he will intently seek death instead. When escape is no longer possible...

Ishikawa Goemon:
[Goemon continues] "He will burn his face with fire... and if fire be not at hand, he will disfigure his face with his sword... and thus, no one will ever know his true identity... He was born in darkness and he will die in darkness... This is the path of the ninja's life, it is the path of death".

Sanday? Momochi:
[In his guise as Fujibayahi Nagato] A samurai's most prized virtue is the ability to indulge in shame. A Ninja, on the other hand, in order to complete a mission... must be crafty, deceptive, dishonest... and commit whatever vile deeds are necessary.