钱玄同与鲁迅早在留学日本时已有同学之谊,“五四”文学革命时期,两人更成为携手并肩共同向旧思想、旧文学挑战的战友。这时他们的私人关系很好,钱玄同常常挟着大皮包,到鲁迅所在的绍兴会馆去,相对长宵夜谈。但“五四”落潮以后,特别是1926年夏鲁迅离京南下以后,两人关系却逐渐疏远以至不相往来。1929年鲁迅回北平省亲时,偶遇钱玄同,这一对当年的密友,竟为了一张名片上的姓名问题弄得很不愉快。钱玄同后来追忆这件事时这样写道:鲁迅到孔德学校访一位朋友,我恰也在那里谈天,“看见他的名片还是‘周树人’三字,因笑问他,‘原来你还是用三个字的名片,不用两个字的’。我意谓其不用‘鲁迅’也。他说,‘我的名片总是三个字的,没有两个字的,也没有四个字的’。他所谓四个字的,大概是指‘疑古玄同’吧。我那时喜效古法,缀‘号’于‘名’上,朋友们往往 Qian Xuan Tong and Lu Xun already had the friendship of students as early as when they studied in Japan. During the “May Fourth” literary revolution, the two became the comrades in arms who jointly stood shoulder to shoulder with the old ideas and the old literature. At this time, their personal relationship is very good, Qian Xuan Tong often carry large purses to the Shaoxing Hall where Lu Xun is located, relatively long night talks. However, after the ebb of “May Fourth” emaciation, especially after Shalhun Xun left the capital in 1926, the relations between the two peoples were gradually estranged and disregarded. When Lu Xun returned to Peking Province in 1929, he encountered Qian Xuan Tong, a close friend of the year, who made a very unpleasant question on the name of a business card. When Qian Xun Tong later recalled the incident, he wrote: When Lu Xun visited a friend at Comte School, I just talked to him. “I saw his business card or the words” Or use three words of business cards, not two words ’.I mean it does not have to’ Lu Xun ’also, he said,’ my business card is always three words, no two words, no four words ’He said the so-called four-word, probably refers to the suspect ancient mysterious with it.