"All rotating things have a spontaneous force and thus their motion is not imposed on them from outside." (Chang Tsai)
"By enlarging one's mind, one can enter into all the things in the world [to examine and understand their principle]. As long as anything is not yet entered into, there is still something outside the mind. The mind of ordinary people is limited to the narrowness of what is seen and what is heard. The sage, however, fully develops his nature and does not allow what is seen or heard to fetter his mind. He regards everything in the world to be his own self. This is why Mencius said that if one exerts his mind to the utmost, he can know nature and Heaven. (1) Heaven is so vast that there is nothing outside of it. Therefore the mind that leaves something outside is not capable of uniting itself with the mind of Heaven. Knowledge coming from seeing and hearing is knowledge obtained through contact with things. It is not knowledge obtained through one's moral nature. Knowledge obtained through one's moral nature does not originate from seeing or hearing." (Chang Tsai)
"Every birth is a condensation (of Qi). Every death is a dispersal (of Qi). Birth is not a gain; Death is not a loss. When condensed, Qi becomes a living thing, when dispersed, it is the substrata of mutation." (Chang Tsai)
"Everything is destiny. A man should accept obediently what is correct [in his destiny]." If one obeys the principles of his nature and destiny, he will obtain what is correct in them. If one destroys principle and indulges in desires to the limit, he will be inviting evil fortune." (Chang Tsai)
"From the Great Vacuity, there is Heaven. From the transformation of material force, there is the Way. In the unity of the Great Vacuity and material force, there is the nature (of man and things). And in the unity of the nature and consciousness, there is the mind." (Chang Tsai)
"He who understands virtue will have a sufficient amount, that is all. He will not allow sensual desires to be a burden to his mind, the small to injure the great, or the secondary to destroy the fundamental." (Chang Tsai)
"Human nature at its source is absolutely tranquil and unaffected by externality. When it is affected by contact with the external world, consciousness and knowledge emerge. Only those who fully develop their nature can unify the state of formlessness and unaffectedness, and the state of objectification and affectedness." (Chang Tsai)
"In one's words there should be something to teach others. In one's activities there should be something to serve as model for others. In the morning something should be done. In the evening something should be realized. At every moment something should be nourished. And in every instant something should be preserved." (Chang Tsai)
"Material force moves and flows in all directions and in all manners. Its two elements unite and give rise to the concrete. Thus the multiplicity of things and human beings is produced. In their ceaseless successions the two elements of yin and yang constitute the great principles of the universe." (Chang Tsai)
"The Great Void cannot but consist of ch’i; this ch’i cannot but condense to form all things; and these things cannot but become dispersed so as to form (once more) the Great Void." (Chang Tsai)
"The great benefit of learning is to enable one to transform his physical nature himself. Otherwise he will have the defect of studying in order to impress others, in the end will attain no enlightenment, and cannot see the all-embracing depth of the sage." (Chang Tsai)
"The Great Harmony is called the Way (Tao, Moral Law). It embraces the nature which underlies all counter processes of floating and sinking, rising and falling, and motion and rest. It is the origin of the process of fusion and intermingling, of overcoming and being overcome, and of expansion and contraction. At the commencement, these processes are incipient, subtle, obscure, easy, and simple, but at the end they are extensive, great, strong, and firm. It is ch'ien (Heaven) that begins with the knowledge of Change, and k'un (Earth) that models after simplicity. That which is dispersed, differentiated, and capable of assuming form becomes material force (ch'i), and that which is pure, penetrating, and capable of assuming form becomes spirit. Unless the whole universe is in the process of fusion and intermingling like fleeting forces moving in all directions, it may not be called Great Harmony." (Chang Tsai)
"The Great Vacuity is clear. Being clear, it cannot be obstructed. Not being obstructed, it is therefore spirit. The opposite of clearness is turbidity. Turbidity leads to obstruction. And obstruction leads to physical form. When material force is clear, it penetrates; and when it is turbid, it obstructs. When clearness reaches its limit, there is spirit. When spirit concentrates, it penetrates like the breeze going through the holes (of musical instruments), producing tones and carrying them to great distances. This is the evidence of clearness. As if arriving at the destination without the necessity of going there, penetration reaches the highest degree." (Chang Tsai)
"The integration and disintegration of material force is to the Great Vacuity as the freezing and melting of ice is to water. If we realize that the Great Vacuity is identical with material force, we know that there is no such thing as non-being." (Chang Tsai)
"When a thing first comes into existence, material force comes gradually into it to enrich its vitality. As it reaches its maturity, material force gradually reverts to where it came from, wanders off and disperses. Its coming means positive spiritual force (shen), because it is expanding (shen). Its reversion means negative spiritual force (kuei), because it is returning (kuei)." (Chang Tsai)
"When one knows that the Great Void is full of ch’i, one realizes that there is no such thing as nothingness." (Chang Tsai)
"When the ch’i condenses, its visibility becomes apparent so that there are then the shapes (of individual things). When it disperses, its visibility is no longer apparent and there are no shapes. At the time of its condensation, can one say otherwise than that this is but temporary? But at the time of its dispersing, can one hastily say that it is then non-existent?'" (Chang Tsai)
"When it is understood that the Vacuity, the Void, is nothing but material force, then existence and nonexistence, the hidden and the manifested, spirit and eternal transformation, and human nature and destiny are all one and not a duality. He who apprehends integration and disintegration, appearance and disappearance, form and absence of form, and trace them to their source, penetrates the secret of Change." (Chang Tsai)
"When the Way of Heaven [or principle] and the nature of man [or desires] function separately, there cannot be sincerity. When there is a difference between the knowledge obtained by following (the Way of) Heaven and that obtained by following (the nature of) man, there cannot be perfect enlightenment. What is meant by enlightenment resulting from sincerity is that in which there is no distinction between the Way of Heaven as being great and the nature of man as being small." (Chang Tsai)
