“What is felt in the heart is ten, what appears in movement seven.”
This expression refers to the following. When a beginner studying the Noh theater learns to gesture with his hands and to move his feet, he will use all his energies to perform in the way in which he is instructed. Later however, he will learn to move his arms to a lesser extent than his own emotions suggest, and he will be able to moderate his intentions. This phenomenon is by no means limited to dance and gesture. In terms of general stage actions and posture, no matter how slight a bodily action, if the motion is more restrained than the emotion behind it, the body will become the Substance and the emotion its Function, thus moving the audience.
from ‘A Mirror Held to the Flower‘ (1424) On the Art of the Noh Drama: The Major Treatises of Zeami, English translation J. Thomas Rimer and Yamazaki Masakuzu, Princeton U. Press, 1984.