The Study of Wuji in the Sword (無極劍學) from the Study of Bagua Sword (八卦劍學)

無極劍學

劍學之無極者，當人執劍身體未動之時也，此時心中空空洞洞混混沌沌一氣渾然，此理是一字生這〇，一字者先天之至道，這〇者無極之形式，是先天一字之所生。人生在世，未嘗學技動作自然，是道之所行，是一字也。及手執劍正立身體未動，是一字生這〇也。譬諸靜坐功夫，未坐之時，呼吸動作是先天道之自然之所行，如同一字也。甫坐之時，兩腿盤跌兩目平視，雖未垂簾觀玄兩手打扣，而心中空空洞洞無思無想一氣渾然，如同〇也。及心神定住，再扣手垂簾塞兌觀玄，又如同這矣。所以劍學與丹道，初無差別，分之則二合而為一，是即劍學無極之理，天地之始也。或者丹書雲：道生虛無，返回練虛合道，是此意也。學者細參之，此理大中秘密言之。

孫祿堂

"The study of Wuji in the sword refers to a man standing and holding the sword, and his body not yet moving. At this moment the center is empty and formless, the unified qi is undivided. This principle is represented by an empty circle, this character (the circle) and the pre-natal heaven follow the same way. The circle is the form of Wuji, it is the symbol of the creation of the Pre-natal. When people are born into the world, before they had learned skills, their natural movements are spontaneous in the Taoist way. When one holds the sword and stands up before the start of the movement, the symbol of the circle is generated.It is like doing sitting meditation, without sitting. Breathing is natural as the pre-natal dao, as the symbol (circle). At the time of sitting, both legs drop and both eyes look levelly ahead. Although you are not blindfolded, you still see the darkness, both hands closed. The interior is empty; there are no thoughts, no consideration, the one qi is undivided as the circle. The attention is still, again the hands turn inward and hang like a curtain, stop looking, this is like a dot in a circle. There is no difference between the study of the sword and the Daoist alchemy, the two are one. The principles of Wuji in the study of the sword are the same of those of the beginning of the world. The Dan Shu says “the Dao is born out of empty nothing, the practice of returning joins the Emptiness to the Dao”, this is the meaning. The student must pay detailed attention; this principle is one of the major secrets."

起點面正，身子直立不可俯仰，兩手下垂直，兩足為九十度之形式。右手執劍，手為中陰中陽之訣式，劍尖與劍把橫平直，左手五指伸直手心靠著腿，兩手兩足不可有一毫之動作。心中空空洞洞，意念思想一無所有，兩目望平直線看去，亦不可移轉，將神氣定住。此式自動而靜由一而生這〇，即為無極形式，內中一切情形與八卦拳學無異，此道執械則為劍，無械即是拳，所以八卦拳學於各種器械莫不包含，學者可與八卦拳并參之。

"The starting point is to look upright. The body stands upright, it should not pitch forward or backward. Both hands hand down straight. The feet form a 90 degree angle. The right hand holds the sword. The hand shape middle Yin middle Yang is the secret. The point of the sword together with the sword handle are leveled. The five fingers of the left hand are stretched out, the palm is near the leg. Neither hands nor feet should have one bit of movement. The mind is empty. There are not thoughts at all. Both eyes gaze at the horizon. The sight is set at the distance, it does not wander around. The vitality shall be present. This form is naturally moving and yet still, one is born from zero, this is the Wuchi form. In all circumstances it is part of the Study of Bagua Quan. This is the way to hold a weapon and make it function as a sword. Because the study of the fist is without weapon, the study of Bagua Quan includes all kinds of weapons. The student can combine (the study of the sword) with Bagua Quan."

From the book The Study of Bagua Sword (八卦劍學), by Sūn Lùtáng (孫祿堂), based on the translation by Joseph Crandall

The Explanation of Tai Chi Chuan's Harmonious Stepping in Four Sides of Pushing Hands (太極拳合步四正推手解)

太極拳合步四正推手解
太極拳以練習推手為致用，學推手刖即是學覺勁,有覺勁刖懂勁便不難矣。故總論所謂由懂勁而階及神明，此言即根於推手無疑矣。掤，履，擠，按四式即黏，連，貼，隨捨己從人之定步推手。

楊澄甫

"Taijiquan uses the practice of pushing hands because of its delicate appplication. Learning pushing hands means learning Feeling Jin. When there is Feeling Jin, the Understanding Jin is not difficult. Therefore, the Total Thesis (of Taijiquan) said: «from Understanding Jin then gradually reach the spiritual enlightenment». There is no doubt that these words are in the basis of pushing hands. Peng (Ward Off), Lu (Rollback), Ji (Press), and An (Push) are the four patterns of adhering, connecting, attaching and following of selfless yielding in fixed-step push hands."

Dictated by Yang Chengfu (楊澄甫口述), noted by Chen Weiming (陳微明筆述), based on the translation by by Yang Jwing Ming (楊俊敏) presented in the book Tai Chi Secrets of the Yang Style (太極拳楊氏先哲秘要) and various translations on the internet

Three Emptinesses

The term "Empty" or "Emptiness" is often used in Internal Martial Arts (内家武術) translations, in particular those that are somewhat older. In fact, whenever reading a text that mentions "emptiness" in a western language one should be aware that it can point to three different notions.

空

The first translation is what I would call "literal" emptiness, the notion that something has been emptied, is vacant, unoccupied. This term is kōng (空), and it describes a wide range of things: the outer space in astronomy (太空), the vacuum (真空), a cavity (空洞), a vacancy (空缺) or a "liberty" in the game of go.

In the internal martial arts texts I've seen, this term is used mostly linked to physical postures, like the necessity of emptying the chest. For example in "Cover" (扣) from the "Xingyi Eight Characters Secret" (形意八字訣) by Jiāng Róngqiáo (薑容樵):

一。兩肩要扣，則前胸空闊，氣力到肘。

"Both shoulders should be like covers. The chest is empty and broad. The qi strength arrives in the elbows."

虚

A second translation is mostly in Tai Chi Chuan (太極拳), and it relates to the way movement is made in Tai Chi. Earlier translations would talk about "full" (實) and "empty" (虚) for the weight for example. I think a better translation for this "fullness" and "emptiness" is given by Yang Jwing Ming (楊俊敏): "substantial" (實) and "insubstantial" (虚). The idea of emptiness here is an idea of void, often in what in the West would be seen as a negative sense: a false reputation (虚名), vanity (虚荣心) or fictitious or theoretical (虚拟). In the Tai Chi Chuan texts, the term is quite central to the practice, for example in the The Ten Important Points of Tai Chi Chuan (太極拳十要) by Yáng Chéngfǔ (楊澄甫):

太極拳術以分虛實為第一義

"The discrimination of insubstantial and substantial is the most important content in Taijiquan. "

無
極

Although much more rarely, the third term that is sometimes translated as "emptiness" or a related term is Wú​jí (無極). It is a term related to chinese cosmogony, as it refers to the potential state the universe was before the "Ten Thousand Beings" appeared (萬物). In internal martial arts, Wú​jí is used to denote the initial undifferentiated state, before a form is started. In some old translations or internal martial arts books, we would see "emptiness" or "empty oneself" related to that specific point.

The term has been introduced in the Internal Martial Arts universe by Sūn Lùtáng (孫祿堂) and Jiāng Róngqiáo (薑容樵), in texts like "The Song of Wújí" (無極歌) by Jiāng Róngqiáo (薑容樵) and "The Study of Wuji in the Sword" (無極劍學) by Sūn Lùtáng.

Chapter 36 (三十六) from the Dào​dé​jīng (道德經)Capítulo 36 (三十六) do Dào​dé​jīng (道德經)

三十六

將欲歙之，必固張之。
將欲弱之，必固強之。
將欲廢之，必固興之。
將欲奪之，必固與之。
是謂微明。
柔弱勝剛強。
魚不可脫於淵，
國之利器，不可以示人。

老子

"When one is about to take an inspiration, he is sure to make a (previous) expiration;
when he is going to weaken another, he will first strengthen him;
when he is going to overthrow another, he will first have raised him up;
when he is going to despoil another, he will first have made gifts to him.
This is called 'Hiding the light.'
The soft overcomes the hard; and the weak the strong.
Fishes should not be taken from the deep; instruments for the profit of a state should not be shown to the people."

Unless noted otherwise, all quotations of classical texts and accompanying translations come from the Chinese Text Project

"Para querer iniciar o recolhimento
É necessário consolidar a expansão
Para querer iniciar o enfraquecimento
É necessário consolidar o fortalecimento
Para querer iniciar o abandono
É necessário consolidar o amparo
Para querer iniciar a subtração
É necessário consolidar o aumento
Isto se chama breve iluminação
O suave e o fraco vencem o rígido e o forte
Os peixes não podem separar-se do lago
O reino que tem o instrumento afiado
Não pode colocá-lo à vista do homem"

Tradução de Wǔ Rǔqīng (武汝清)

The Song of Six Coordinations (六合歌) by Jiāng Róngqiáo (薑容樵)

六合歌

身成六式，
雞腿龍身，
熊膀鷹爪，
虎抱雷鳴。

薑容樵

"The whole body has six forms,
Cock legs, dragon body,
Bear arms, eagle claws,
Tiger’s embrace and the sound of thunder.

From the book Xing Yi Mother Fists (形意母拳), by Jiāng Róngqiáo (薑容樵), based on the translation by Joseph Crandall