思过半矣[sī guò bàn yǐ]
词典can largely comprehend the rest：思过半矣。
can largely comprehend the rest
1. 虽未能尽愈诸病，庶可以见病知源。若能寻余所集，思过半矣。 Although it failed to cure all diseases, it could be known about the origin of diseases.