Excerpt from <span class="chinese-post-title">李存義先生言</span> Report of Lǐ Cúnyì Sayings in <span class="chinese-post-title">拳意述真</span> Boxing Concepts Explained Authentically

一則

李存義先生言。拳經云。靜為本體。動為作用。寂然不動。感而遂通。是化勁練神還虛之用也。明暗勁之體用。是將周身四肢鬆開。神氣縮回。而沉於丹田。內外合成一氣。再將兩目視定彼之兩目。或四肢。自己不動。而為體也。若是發動。剛柔曲直。縱橫圜研。虛實之勁。起落進退。閃展伸縮。變化之法。此皆為用也。此是與人相較之時。分析體用之意義也。若論形意拳本旨之體用。是自己練蹚子為之體。與人相較之時。按練時而應之為之用。也虛實變化不自專用。因彼之所發之形式。而生之也、

郭雲深

"It says in the Boxing Classics: “Stillness is the fundamental form. In movement lies the function.” By being silent and still, then upon sensing anything, you connect with it. This is the function of neutral energy, of training spirit and returning to emptiness. The form and function of the obvious and hidden energies are in getting your whole body and every limb to relax. Spirit and energy shrink in and sink to your elixir field. Inside and outside merge to become a single continuum.
Then look with your eyes right into the opponent’s eyes or to his four limbs. When you are unmoving, this is the form. But as soon as you move, there is hardness and softness, bending and straightening, crissing and crossing, circling and grinding – these are the emptyings and fillings of energy. There is lifting and dropping, advancing and retreating, evading and extending, extending and contracting – these are the variations of technique. All of these form the function.
When you are competing with opponents, distinguish the meanings of form and function. To describe the original notions of form and function in Xingyi Boxing, going through the solo practice is the form, whereas competing with others and training in how to respond is the function. The transformations of empty and full are not a matter of your own design, but are to be generated by the postures brought forth by the opponent."

Excerpt from the translation by Paul Brennan, to be found in the Brennan Translation blog.