Are suffixes etymological, or is it just "how it sounds"? [ie; Marxist vs Keynesian]

Miscellaneous General
1

Hello

Just enquiring as to how suffixes are agreed upon, for instanced, Karl Marx ideas become Marxist, whilst John Maynard Keynes type-ideas become Keynesian.

Are these decisions etymological, ie; Greek suffixes vs Latin suffixes, are or they to do with the syllabels and character used, ie; how it sounds?

Panarchy

2

“Marxist” probably arose due to association with “communist” and “socialist”. However, many economists (e.g. Mises) use the term “Marxian” instead.

“Keynesian” follows the convention of adjectives derived from personal names: Kantian, Lockean, Hobbesian, Aristotelian, etc.