論商業契約的履行與免責—以美國法為中心

Impossibility, Impracticability, Frustration and Mistake in Commercial Contracts: From the Perspective of American Law

駱建廷(Chien-Ting Lo)

指導教授 ： 王文宇

國立臺灣大學/法律學院/法律學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.10105

摘要

在商業環境的快速發展以及交易關係由個別交易推展至遍佈全球的演進趨勢中，契約一直扮演著型塑交易內容、提供交易參加人保障的重要角色。而隨著交易型態的複雜化以及世界經濟體制的整合趨勢，交易關係已經不若以往的以物易物那樣單純：契約的訂定者勢必得嘗試以更加宏觀、更加具備前瞻性的眼光來看待交易關係。然而，外在環境的複雜程度以及人類的有限理性，卻相當程度的拘束著人們完善規劃並順利地依計畫完成交易的可能性，使得原本以形塑交易雙方均等權利義務關係為目的的白紙黑字，成為了扭曲市場最佳效率的青面獠牙。在這樣的情形下，契約訂定者究竟應該如何避免以契約作繭自縛？而社會制度形成催生者：立法者與司法者，又應當以何種角度來嘗試弭平不可預料的情形為交易公平性帶來的衝擊？即為本文所欲討論者。

本文嚐試將契約法律關係以締約作為分界點，於第二章中立於契約締結者的角度，藉由交易成本理論、不完全契約理論、關係契約理論等經濟學理論之闡述，試圖在經濟與法律制度的交互作用之下，將締約人於商業契約成立前所應思考、應磋商、應解決之問題予以分析，討論商業契約的締結應以何種思考基礎來試圖藉由風險分配、節省交易成本等角度，減低日後因外在環境變化對交易雙方帶來的衝擊。

其次，於第三、四章中，本文即將立於立法者、司法者的角度，藉由不同法律制度的闡述，來討論契約成立後發生出乎締約人意料的外在環境改變發生時，應如何處理契約雙方的爭議。而於第三章中，本文先以介紹美國法關於履行不能、履行艱難、目的受挫、錯誤等契約法概念，輔以美國的判例、成文法及權威性理論，以為借鏡；隨後，即將就我國民法中相對應之制度—情事變更原則與意思表示錯誤撤銷制度，為一要件及法律效力上的剖析，並援引我國之實務見解，分析我國法制上之相關缺失，並提出本文之建議。

關鍵字

商業契約 ； 交易成本 ； 履行不能 ； 履行艱難 ； 目的受挫 ； 錯誤 ； 情事變更

並列摘要

In the trend that the commercial environment is developing extremely fast, and transactional relationships are also transforming from discrete transactions to a world-wide basis, contract has been playing an important role, which not only forms the structure of transactions, but also provides the participants in a transaction with basic guaranty. At the mean time, since the increasing complexity of transaction forms and the unity of global economical systems have shifted the nature of transaction relationships from simplicity to a much more complex scenario, contractors have to take a wider and proactive view towards transactions. However, the changeable environment and the limited rationality of human have all become restrictions that prevent contractors from planning in detail and fulfilling the plans successfully; in that, contracts, which are originally made to influence transactions, have become burden rather than relieve in unpredictable events or change of circumstances. In this thesis, I will try to both discuss how would a contractor do in order to prevent the backfire of contract-making in changed circumstances, and how should the legislators and the judicial systems solve the disputes around whether the contract should be discharged or enforced.

First, in Chapter 2, I will try to stand in the contractor’s shoes, by elaborating some economical and law theories such as Transaction Cost Theory、Incomplete Contracting Theory、Relational Contract Theory, try to develop and analysis what should contractors do to consider、negotiate、figure out salvations before a commercial contract is entered into, and on what basis, such as transaction cost saving、risk allocating, should the contractors stand on in order to reduce the negative effect toward parties.
Secondly, in Chapter 3 and 4, I will look from the legislator and the judge’s point of view, developing when unpredictable changes of circumstance occur, how should the dispute of whether to discharge the obligator or not be resolved. In Chapter 3, I will first illustrate concepts like Impossibility、Impracticability、Frustration of Purpose and Mistake, and combine them with the case law、written law and statements of law, to shape the contract discharging system of American law. Then I will discuss the corresponding term in the Civil Code of Taiwan—“the Doctrine of Change of Circumstances” and “Rescind of Mistaken Promises”. By way of analyzing the articles and court opinions, I will point out the shortcomings and defects in these regimes, while also making further suggestions on them.

並列關鍵字

Commercial Contracts ； Transaction Cost ； Impossibility ； Impracticability ； Frustration of Purpose ； Mistake ； Doctrine of Change of Circumstances.

參考文獻

3.林誠二，「再論誠實信用原則與權利濫用禁止原則之機能—最高法院八十八年度台上字第二八一九號判決評釋」，台灣本土法學雜誌，第22期，第36頁。

7.黃湘榆，「計畫趕不上變化?論長期商業契約中之風險控制與漏洞填補—以契約之解釋為中心」，台灣大學法律學研究所碩士論文，2008年7月。

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