Where does “ことなかれ主義” come from?

ことなかれ主義 (Japanese) comes from Japanese 主義, from English -ism, from Latin -ismus, from Ancient Greek -ισμός, from Ancient Greek -μός, from Proto-Indo-European -mós — Creates action/result nouns from verb stems.

ことなかれ主義 (Japanese): philosophy of not rocking the boat

Definitions

philosophy of not rocking the boat

Ancestry of “ことなかれ主義”, step by step

ことなかれ主義 traces back through 3 separate lines of ancestry.

via Japanese 主義

Step	Language	Word	Meaning
1	Japanese	主義	a principle or set of principles; a doctrine; an...
2	English	-ism	Used to form nouns of action or process or result...
3	Latin	-ismus	-ism
4	Ancient Greek	-ισμός	Forms abstract nouns
5	Ancient Greek	-μός	Forms abstract nouns
6	Proto-Indo-European	-mós	Creates action/result nouns from verb stems

via Japanese なかれ

Step	Language	Word	Meaning
1	Japanese	なかれ	must not; do not
2	Japanese	あれ	distal demonstrative, something far off removed...
3	Japanese	あ	expresses surprise: Ah! Oh!; used to get...
4	Japanese	あり	有り existing; 蟻 ant

via Japanese こと

Step	Language	Word	Meaning
1	Japanese	こと	broadly, any abstract thing, affair, matter, or fact
2	Japanese	事	thing, fact, event; thing; stuff; abstract thing
3	Middle Chinese	事	—

Every word from Proto-Indo-European -mós →Every word from English -ism →Every word from Ancient Greek -μός →