晋朝的著名画家顾恺之，
学问深、绘画好谈吐尤风趣。
时人送个外号称“三绝”，
说他是“才绝”“画绝”“性绝痴”。
南北朝梁代有个张僧繇（yáo），
他的画艺很高名气大，
他擅长画山水人物和佛像，
不知者往往认画作真物。
武帝时兴建的许多寺院和佛塔，
里头有许多佛像是他亲手画。
传说他曾在庙壁画了四条龙，
每条龙都不把眼睛画。
朋友们劝他把龙眼给点上，
龙无眼睛不传神太可惜。
大家再三恳求下，
僧繇难拂众人意，
提起画笔点两点，
两声响，点睛的两龙破壁腾空向天去。
未点睛的两条还在墙上趴，
众人吓得四散去。
这故事虽然离奇又荒诞，
但却能说明一个道理：
僧繇所以威望高，
因他作画有好功底。
唐代也有个画家叫吴道子，
画山水画佛像有造诣，
笔法绝妙人称赞，
无人能和道子比。
传说他为玄宗画了幅嘉陵山水画，
一天内画完了山水三百里。
他还在景玄寺画了幅《地狱变相图》，
没鬼怪那阴森的气氛却也把人逼。
甚至于有人看了这幅画，
发誓永不干坏事。
三位画家成历史，
后人赞誉常提起。
顾恺之画技超前人，
张僧繇画技无人及，
吴道子成就以前不曾有，
往后也难有人超过吴道子。
后人提起画坛事，
得出了“空前绝后”这成语，
常形容某种艺术成就高，
或者是某件事物极稀奇。
独一无二最罕见，
绝非其他能相比。
A Thing Never Existed in the Past，
and Will Never Happen in the Future
In the Jin Dynasty（265—420A。D。），there was a famous artist named Gu Kaizhi，who was learned and eloquent and humourous。The people called him“a man of three talents”，saying he was brilliant in intelligence，in painting and in personality。
In the reign of the Liang Generation in the Southern-and-Northern Dynasty（420—589A。D。）there was an artist named Zhang Sengyao，whose fame went down to the later generations。He was especially good at painting mountains，rivers，people and the Buddha。One might have mistaken the scenery in his paintings for real things if he or she did not have insight。Inside quite a lot of temples and Buddhist pagodas set up during the reign of Emperor Wu of Han Dynasty there were many of his masterpieces。
The legend goes that he drew four dragons on the walls in a temple，but on each of the four dragons'heads he deliberately omitted the eyes。His friends asked him to add the eyes，saying that they would carry no spirit without eyes。Being asked again and again many times，Sengyao found it hard to refuse。He picked up his brush and made two strokes，and the two dragons flapped and puffed and soared into the skies。The two dragons without eyes still remained on the wall，but the on-lookers were frightened and all ran away。
This story of course was funny and unbelievable，but it appeared to us to be a very good idea：Sengyao was literaly honoured only because he had gained a good mastery of craftsmanship。
In the Tang Dynasty there was an artist named Wu Daozi，who was also good at painting mountains，rivers and Buddhas。He also possessed an unique style，that no-one could take from him or keep abreast of。The legend goes that he drew the landscape of Jialing Mountain and water。He covered three hundred li in a single day。He also painted“A Altered Picture of the Hell”in the Jingxuan Temple which created a petrified atmosphere without showing a ghost。It is said that if a vicious man saw it，his resolve would never be as bad again。
The three artists became historical sages，and the later generations often remember them。Gu Kaizhi overtook his predecessors，Zhang Sengyao excelled his contemporaries，and Wu Daozi was once unprecedented，and was surely unrepeatable。
Later on when talking about something in the art circle，people use this very idiom to describe something of a great feat。Or to say that something is very rare，or when you want to say something is unique and nothing can equal to it。
