noun
Refers to logical consistency, uniformity, or lack of contradiction in ideas, actions, or policies.
彼の主張には一貫性がない。
His arguments lack consistency.
この計画には一貫性が必要
This plan needs coherence.
矛盾 means 'contradiction' or 'inconsistency', the opposite of 一貫性.
Compound of 一貫 (いっかん, 'consistent, through') and 性 (せい, '-ness, nature').