Note #2
There are methods to observe people and undoubtedly recognise the manner
how they think and their character. We say that the Self closely listen
the heart, observe him, that he can be seen and understood as an image
in a mirror. The one who have a disturbed heart can be quickly be the
victim of others. That’s why the shinobi use this technique and can
follow everywhere the heart of the adversary and penetrate him. This is
the basics technique of the shinobi.
-- Shôninki – Natori Masazumi
-- Shôninki – Natori Masazumi