"If you master this technique, you'll gain an overwhelming advantage over other ninjas and naturally become a Jonin.."
Sarutobi Hiruzen continued,
"Of course, that's only the surface of Chakra Nature Transformation.."
"In essence, the nature transformation of Chakra—even Chakra itself.."
Sarutobi Hiruzen paused and looked at Uchiha Itachi with a deep gaze, speaking with a note of feeling,
"Is, at its core, the power of 'belief.'"
Uchiha Itachi murmured, somewhat puzzled.
"The power of belief?"
Uchiha Shisui, however, grew serious. He knew what came next might be a secret so closely guarded it belonged in the Scroll of Sealing.
"That's right.."
Sarutobi Hiruzen said,
"Chakra is energy made up of physical and spiritual strength,"
"And the Hand Seals ninjas use are also meant to help focus their spiritual strength."
"Chakra Nature Transformation, at its core, is about strengthening your will and spirit,"
"Strengthening your 'belief.'"
"That way, when you transform Chakra into a nature-based technique, you increase its tangible power."
Sarutobi Hiruzen had the foundation of a Professor of Ninjutsu, and had also absorbed the knowledge systems of modern society.
He had developed his own understanding of the ninja path.
In truth, every supernatural system contained elements that defied science, simply by virtue of being supernatural.
In Sarutobi Hiruzen's understanding, Chakra could accomplish all kinds of incredible feats, including the five nature transformations, creating something from nothing, and resurrecting the dead.
What set it apart from science more than anything was "belief," or, in other words, spiritual will.
"As long as your willpower and spiritual strength are strong enough,"
"You can make flames burn hotter and lightning flash with greater force!"
Sarutobi Hiruzen casually picked up a leaf and let a little Chakra seep into it. The leaf grew hot and burst into flames.
Even after the leaf had burned