adverb
therefore; and so; for that reason
A formal or literary conjunctive adverb indicating a logical consequence. Often used in written arguments or explanations.
彼は証拠を隠した。それゆえに有罪と判断された。
He hid the evidence. Therefore, he was judged guilty.
この問題は複雑である。それゆえに、慎重な対応が必要だ。
This issue is complex. For that reason, a careful response is necessary.
だから is a more casual, everyday conjunction meaning 'so' or 'therefore'. それゆえに is more formal and literary, often used in written or structured arguments.
したがって is also a formal conjunctive adverb meaning 'accordingly' or 'consequently'. It is similar in register to それゆえに, but それゆえに can sound slightly more emphatic or literary.
Compound of それ (that) + 故に (due to, because of). The kanji 故 carries the meaning of 'reason' or 'cause'.