《史记·七十列传·扁鹊仓公列传》
如果不能精心切脉，所断定的死生时间及能否治愈，也往往会出现差错，我不能完全没有失误。 
心不精脉，所期死生视可治，时时失之，臣意不能全也。 
If I do not take the pulse carefully, my predictions about whether the patient will live or die or whether the condition can be cured are often wrong, and I cannot be completely without error.