民事訴訟法自2000年修正採取「集中審理主義」結合「適時審理主義」之審理結構後，學者紛紛援引德、日學說，就與民事集中審理密切相關之「訴訟促進義務」以及「逾時提出攻擊防禦方法之失權制裁」進行論述。然而，多數學說所呈現之關懷重心，幾乎均置於逾時提出攻防是否將導致「訴訟延滯」之問題上，而將失權制裁之目的定位於「效率性」價值之追求，並在此主軸上開展相關之解釋論。本文旨在對此種論述發展之傾向提出檢討，主張就逾時攻防課予失權制裁，其目的不應純然取向於效率性價值之追求，而係亦蘊含有「當事人間公平」之價值以及「程序正義」之實踐。本文並藉由具體爭議問題之檢討，進一步論證「效率」與「公平」兩個不同之基本價值取向，不僅將影響法院對失權制裁之解釋操作，亦將進而直接影響訴訟勝敗之結果，對當事人程序權與實體權之保護，關係至為重大。本文期待藉由一個完全不同考察視野之提出，一方面深化就失權制度之學術理論上對話，一方面為法院就此制度之適用與解釋，提供若干參酌。

Taiwan adopted a landmark reform to abolish the traditional continental system's episodic hearings and to move towards a concentrated proceeding in the 2000 Amendments to the Taiwan Code of Civil Procedure. To implement this reform, a duty is imposed on parties to expedite the proceeding and the court can preclude any materials submitted in violation of this duty. Since the preclusion effect of untimely-raised issues significantly influences case outcomes, how to apply this new mechanism becomes controversial. Most Taiwanese scholars, relying upon the German theories, place great emphasis on the value of efficiency in justifying this preclusion effect as well as in interpreting relevant rules. This article challenges this line of reasoning and argues that fairness is also an important, even more important, value underlying this preclusion effect. To preclude a party from untimely raising a new issue is not merely for the purpose of pursuing efficiency, but is also for the purposes of protecting the opposing party from surprise as well as of ensuring fairness. This article further demonstrates that switching the emphasis from efficiency to fairness will have broad implications for applying this preclusion effect and will lead to more sensible conclusions. Finally, this article proposes a theoretical framework under which the value of efficiency can be preserved without impairing the basic rights of the litigants and without undermining the value of fairness.