Translation guide
Describes something that lacks sense or reason. In Japanese, this is commonly expressed with words like 非論理的 (non-logical) or 筋が通らない (doesn't make sense). The best choice depends on whether you're describing an argument, a person's thinking, or a situation.
When an argument, statement, or conclusion does not follow from the premises or evidence.
The most direct translation, meaning 'not logical'. Used for formal or academic contexts. It's a な-adjective.
彼の主張は非論理的だ。
His argument is illogical.
Literally 'the logic doesn't go through'. A very common, natural way to say something doesn't make sense or is inconsistent. Used in everyday conversation.
その説明は筋が通らない。
That explanation is illogical.
Means 'doesn't fit reason'. Slightly more casual than 非論理的, but still clear. Often used when something defies common sense.
彼の行動は理屈に合わない。
His behavior is illogical.
Means 'irrational' or 'unreasonable'. Often used for systems, rules, or decisions that lack logic. A な-adjective.
その規則は不合理だ。
That rule is illogical.
When statements or actions contradict each other, lacking internal consistency.
Means 'contradictory'. Use this when two things cannot both be true. Very common and natural.
彼の言っていることは矛盾している。
What he's saying is illogical (contradictory).
Means 'inconsistent' or 'doesn't add up'. Often used for stories or explanations that have holes.
彼の話はつじつまが合わない。
His story is illogical (doesn't add up).
Describing a person or their actions as not based on reason, often emotionally driven.
Literally 'not rational'. A straightforward way to say someone is not being logical. Can sound a bit formal.
彼は理性的でない判断をした。
He made an illogical decision.
Means 'emotional'. Often used when someone's illogical behavior stems from emotions rather than reason. A な-adjective.
彼女の反応は感情的で非論理的だった。
Her reaction was emotional and illogical.
When something is so illogical it seems ridiculous or makes no sense at all.
Means 'absurd' or 'ridiculous'. Stronger than just illogical; implies foolishness. Casual.
そんな考えはばかげている。
That idea is illogical (absurd).
Loanword from English 'nonsense'. Used similarly to English, often in casual or emphatic contexts.
その提案はまったくナンセンスだ。
That proposal is completely illogical (nonsense).
While 非論理的 is a direct translation, it can sound stiff or academic. In everyday conversation, phrases like 筋が通らない or 矛盾している are more natural. Use 非論理的 mainly in formal writing or debates.
非論理的 (hi-ronri-teki) specifically means 'not logical' in the sense of formal logic. 不合理 (fu-gōri) means 'unreasonable' or 'irrational', often implying a lack of fairness or common sense. For a flawed argument, use 非論理的; for an unfair rule, use 不合理.