I was asked why Takamatsu re-wrote the Amatsu Tatara Hisshin Ginkōroku (天津鞴韜謐心誾諕録) Shinshin Shingan no maki ('god's mind / heart and god's eyes' - 神心神眼の巻) documents / scrolls

My feeling is that firstly, as with many languages, the arcane forms of language need to be updated, so that contemporary and future generations can understand them. Otherwise, there is no transmission of knowledge.

Even Takamatsu Sensei's writing from 70 years ago had to be transcribed into a more current version of Japanese, so that it could be translated into English.

Secondly, and in addition, Takamatsu Sensei had the opportunity to update older concept of illness and their symptoms to bring them into line with modern pathological concepts and descriptions. This together with an understanding of anatomy & physiology would have added additional dimensions to the documents and allowed some cross communication with other medical approaches. It is fortunate because without such updates the knowledge contained within these documents would not have remain relevant into the future.

We can sometimes forget that living traditions need to retain effectiveness and that is the responsibility of the lineage holder. Without such updating, a tradition become an anachronism.

The Japanese character for Ryū (流) suggests a flow, or current rather than a stagnation.