夫曰有是病即有是脉者．此亦大概言之．其微渺未必皆可恃乎脉也．如目病．必视其目为内障．为外障．
内障有内障之症．外障有外障之症．必辨其为何症．所中所伤之浅深．果在何轮何廓．辨之明而后治之当．今闺阁处子．暨夫贵介之族．但舒手于帷幔之外．诊其脉即欲治其病．且责其用药当而效之速．不知即方脉之专重乎脉者．尤望闻问居其先．而切脉居于后．盖切而知之．仅谓之巧耳．况症之重者．关乎性命．而惟恃巧以中之．何轻视乎性命耶．必精详审辨．而后治之可也．重性命者．当必以是言为然也．矧目为五官之最要者哉．假令一瞽目．隐身于帷幔之中．舒其手于帷幔之外．其六脉未尝不与有目者相同也．切脉者．从何脉辨知其为瞽耶．恐神于脉者．亦未易知．后学岂能臻此之妙．定其残好．必猜度拟议之．而用药亦猜度拟议之药尔．欲其当而效之速．实难矣．较而论之．两误之中．病者之自误为尤甚也．兹特摘出其弊．必于诊脉之外．更加详视．始不至有误矣．