connective N1 uncommon writtenliterary

故に — therefore / because of ~

故にゆえに

Meaning

① therefore (consequence): therefore / hence / consequently — drawing a conclusion (= だから)

② because of (cause): because of ~ / owing to ~ / on account of ~ (= のために)

① therefore (consequence)

我われ思おもう、故ゆえに我われあり。

I think, therefore I am.

② because of (cause)

貧まずしさ故ゆえに、彼かれは進学しんがくを諦あきらめた。

Because of poverty, he gave up on going to college.

Attaches to	Form	Example
Sentence-initial (consequence)	故ゆえに + clause
Noun (+ の) / plain form + が (cause)	N(の) + 故ゆえに、 plain + が故ゆえに	病気びょうき → 病気びょうき（の）故ゆえに

When: Written, formal, and academic — logical argument, philosophy, legal and formal prose.

① therefore (consequence)

前提ぜんていが誤あやまっている。故ゆえに結論けつろんも誤あやまりだ。

The premise is wrong; therefore the conclusion is wrong too.

証拠しょうこは十分じゅうぶんである。故ゆえに有罪ゆうざいと判断はんだんする。

The evidence is sufficient; hence we find the defendant guilty.

② because of (cause)

若わかさ故ゆえの過あやまちだった。

It was a mistake born of youth.

慎重しんちょうであるが故ゆえに、決断けつだんが遅おそれた。

Precisely because he is cautious, his decision came late.

Jengo shows 故に the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.

Sources Compiled with reference to A Dictionary of Advanced Japanese Grammar.