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.
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.
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.
His behavior is illogical.
Means 'irrational' or 'unreasonable'. Often used for systems, rules, or decisions that lack logic. A な-adjective.
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.
What he's saying is illogical (contradictory).
Means 'inconsistent' or 'doesn't add up'. Often used for stories or explanations that have holes.
His story is illogical (doesn't add up).
Describing a person or their actions as not based on reason, often emotionally driven.
When something is so illogical it seems ridiculous or makes no sense at all.
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.
Her reaction was emotional and illogical.
That proposal is completely illogical (nonsense).