往「還沒定論」的方向
既然兩邊都放得下理由，那就表示還沒有人定得下來——這是核心畫面最直接的一種讀法。
adjective · C1
Not certain and not clearly true, so sensible people can disagree about it and you cannot settle it just by checking.
有爭議的；說不準的
核心畫面
Think of a point where arguing is still possible — there is room around it, and reasons can be put on both sides. That one picture can be read in two directions. Stand on one side and it means nothing here is settled. Stand on the other and it means there is a real case to be made. The word keeps both readings, and the shape of the sentence tells you which one is in play.
可以想成一個還吵得起來的地方：這件事周圍還有空間，兩邊都放得下理由。同一個畫面，可以往兩個方向看。站在這一邊看，是「…更多收起
可以想成一個還吵得起來的地方：這件事周圍還有空間，兩邊都放得下理由。同一個畫面，可以往兩個方向看。站在這一邊看，是「還沒有定論」。站在另一邊看，是「這邊真的有話可說」。arguable 把兩種看法都留著。要分辨是哪一種，看句子的形狀就知道：單獨用，通常是前者；帶著 It is... that 的句型，通常是後者。From the word’s history
Wiktionary gives arguable as argue plus -able, through Old French arguer from Latin arguō 'to make clear, to prove'. So the word is built as 'able to be argued', which is exactly the open space the modern uses divide between them.
Wiktionary 記載 arguable 由 argue 加上 -able 組成，argue 經古法文 arguer 來自拉丁文 arguō（弄清楚、證明）。所以這個字的組成就是「吵得起來的、論證得起來的」。今天的兩個用法，正好是把這塊空間分成兩邊各佔一半。
Wiktionary etymology tree supplied in evidence packet (kaikki:3f6f69a190036ae4:915115906:14547)
Two branches
往「這邊有話可說」的方向
同一塊空間，換成從自己這一側看：既然論證得起來，那我現在就論給你聽。這個讀法只活在 It is arguable that 這個句型裡。
adjective · C1
Used before an idea when you are about to give good reasons for it. You are saying the case for it can be made, without claiming it is certainly true.
可以說…；有理由認為…