Translation guide
Expresses that something is based on theory rather than practice, or exists only as an idea or possibility.
Describing knowledge, a field, or an approach that is abstract and not yet applied.
The most direct equivalent, used for academic or systematic theoretical frameworks.
Referring to an idea, scenario, or possibility that is imagined rather than real.
Emphasizes that something is a hypothesis, not established fact.
それはまだ仮説的な段階だ。
That's still at a theoretical stage.
Describing a discussion or concept that is removed from everyday reality.
理論的 is used for established theoretical frameworks (e.g., theoretical physics), while 仮説的 emphasizes that something is still a hypothesis and not yet proven.
English 'theoretical' can sometimes be translated directly as 理論的, but in casual contexts, it may sound stiff. Consider rephrasing with 理屈っぽい (overly logical) or 現実的じゃない (not realistic) if the nuance is negative.
彼の研究は非常に理論的だ。
His research is highly theoretical.
Often used adverbially to mean 'in theory' or 'theoretically speaking'.
理論上は可能だが、実際には難しい。
Theoretically it's possible, but in practice it's difficult.
An idiom meaning 'armchair theory' or an impractical idea that only works on paper.
その計画は机上の空論に過ぎない。
That plan is nothing more than a theoretical idea.
Suggests something is conceptual or idealistic, sometimes with a nuance of being impractical.
彼の話は観念的すぎて理解しにくい。
His talk is too theoretical to understand easily.
Means 'scholarly' or 'academic', often used when theoretical is contrasted with practical.
それは学問的な興味に過ぎない。
It's merely of theoretical interest.