Classical grammar words in the Dao De Jing
莫 mò
In the Dao De Jing, 莫 (mò) is always the negative pronoun “no one, nothing” (20 times), as in 莫能知, “no one can understand”.
莫 is a negative word that is also a subject: “no one, nothing, none”. 天下莫能知 (chapter 70) is “no one in the world can understand”. It is not a plain “not” (that is 不): it says that, among all the people or things in question, there is none that does it.
In modern Chinese 莫 means “do not” in formal or regional speech (莫急, “don't hurry”), and the old sense lives on in set phrases such as 莫名其妙, “baffling” (no one can name why), and 爱莫能助, “willing but unable to help”.
莫 as “no one, nothing”
Pattern 莫 + verb / 莫 + adjective + 于 + noun
A negative pronoun, “no one, nothing”, standing as the subject of the verb that follows. With 于 “than” it makes a comparison, “nothing is more …”: 祸莫大于不知足 (chapter 46), “No disaster is greater than not knowing what is enough.” 莫不 is a double negative, “none fails to”, that is “all”: 万物莫不尊道而贵德 (chapter 51), “among the myriad things none fails to honor the Way and value virtue.” When the object is the pronoun 之 “it”, it moves before the verb: 莫之能守 (chapter 9), “cannot be defended”.
20 times in 18 lines.
莫之能守。
cannot be defended.
Chapter 9, line 6夫唯不争，故天下莫能与之争。
He does not contend, therefore the world cannot contend with him.
Chapter 22, line 7天下莫能臣也。
no one in the world can make it a subject.
Chapter 32, line 2民莫之令而自均。
and the people, with no one ordering them, would share it evenly.
Chapter 32, line 6上礼为之而莫之应，
Superior ritual acts, and when no one responds,
Chapter 38, line 7祸莫大于不知足；
No disaster is greater than not knowing what is enough;
Chapter 46, line 3
Show 12 more lines
咎莫大于欲得。
no fault is greater than wanting to gain.
Chapter 46, line 4是以万物莫不尊道而贵德。
So among the myriad things none fails to honor the Way and value virtue.
Chapter 51, line 3道之尊，德之贵，夫莫之命而常自然。
The Way is honored and virtue valued not by anyone's command, but always of themselves.
Chapter 51, line 4治人事天，莫若啬。
In governing people and serving heaven, nothing is better than frugality.
Chapter 59, line 1无不克则莫知其极；
when nothing cannot be overcome, no one knows one's limits;
Chapter 59, line 5莫知其极，可以有国；
when no one knows one's limits, one can hold a state;
Chapter 59, line 6以其不争，故天下莫能与之争。
Because he does not contend, no one in the world can contend with him.
Chapter 66, line 9祸莫大于轻敌，轻敌几丧吾宝。
No disaster is greater than underrating the enemy; underrating the enemy nearly loses my treasures.
Chapter 69, line 6天下莫能知，莫能行。
Yet no one in the world can understand them, no one can practice them.
Chapter 70, line 2天下莫柔弱于水，
Nothing in the world is softer or weaker than water,
Chapter 78, line 1而攻坚强者，莫之能胜，
yet for attacking the hard and strong, nothing surpasses it,
Chapter 78, line 2天下莫不知莫能行。
everyone in the world knows it, yet no one can practice it.
Chapter 78, line 6
How to tell them apart
莫 always stands where a subject would: it is the “no one” or “nothing” itself, while 不 only negates a verb. In 天下莫能知 (chapter 70) the world is the field, and 莫 says that no one in it can understand; a 不能 would only say that a given subject cannot.
Chapter 78 shows its two patterns side by side: 天下莫柔弱于水, “Nothing in the world is softer or weaker than water”, the comparison; and 莫之能胜, “nothing surpasses it”, with the object 之 moved before the verb.