論契約損害賠償範圍之因果關係

Abstract

損害賠償乃貫徹我國民事責任體系之核心法律效果，而損害賠償範圍之限制，更為認定損害賠償之關鍵課題。就損害賠償範圍限制而言，在我國現行法制，首要即係透過因果關係之認定為之，並無論於侵權行為法或契約法，均以「相當因果關係理論」作為限制損害賠償範圍之主要機制。然而，契約法係以私法自治與契約自由為根本原則，契約當事人乃於自願之基礎上進入特定法律關係，並得於事前預為風險分配。是以，契約責任體系應首重當事人之意思自治，其責任範圍之界定，亦應與侵權責任有所區別，且必須妥適貫徹私法自治及契約自由原則之基本精神。

為釐清何種理論更能妥適反映契約法律關係之本質與價值，本文將首先檢視我國法及比較法上所採取之主要理論，包括：相當因果關係理論、預見可能性原則與保護目的理論。由於本文之研究焦點在於契約法律關係，故各理論之採納，必須能充分反映契約責任之結構特性與制度目的。再者，本文所欲探討的，本質上即屬於「責任範圍因果關係」之「法律上因果關係」。此一問題非僅為抽象理論之爭，各該理論之良窳，乃繫於個案適用上得否導出合理且一貫之結果，而需具備一致性。是以，若一理論無法兼顧妥適性與理論一致性，其作為限制機制之正當性亦難成立。

本文主張，保護目的理論將契約損害賠償之範圍判斷回歸契約本身之目的與保護範圍，較能體現契約自由與風險分配之精神，並貫徹私法自治原則。此理論不僅能於個案上導出較為妥適之結果，且於理論層面具備一致性與說服力。故我國契約法上之損害賠償範圍限制，宜以保護目的理論為主要依據，而非再以相當因果關係理論為一般性標準。至於相當因果關係理論，宜作為保護目的理論之下位判斷基準，輔助確認契約保護範圍之界限，方能契合契約法之制度特質與規範目的。

Damages constitute the core legal consequence through which the system of civil liability under Taiwanese law is implemented, and the delimitation of the scope of recoverable damages represents a central issue in determining liability. Under the current legal framework, the primary mechanism for limiting the scope of damages—whether in tort or in contract—lies in the determination of causation, with the doctrine of adequate causation serving as the principal limiting device.

However, contract law is founded upon the fundamental principles of private autonomy and freedom of contract. Contracting parties voluntarily enter into legal relationships and are, in principle, able to allocate risks in advance. Accordingly, the system of contractual liability must give priority to party autonomy, and the determination of the scope of contractual liability should be distinguished from that of tort liability, while properly giving effect to the underlying principles of private autonomy and freedom of contract.

In order to clarify which theory more adequately reflects the nature and values of contractual relationships, this article first examines the principal approaches adopted in Taiwanese law and in comparative law, including the doctrine of adequate causation, the foreseeability principle, and the protective purpose theory. Given that the focus of this study lies in contractual relationships, the adoption of any such theory must be capable of fully reflecting the structural characteristics and institutional objectives of contractual liability. Moreover, the issue addressed in this article concerns, in substance, legal causation within the scope of liability. This is not merely an abstract theoretical debate: the merits of each theory depends on whether it can yield reasonable and consistent outcomes in concrete cases. A theory that fails to reconcile substantive appropriateness with theoretical coherence lacks normative legitimacy as a limiting mechanism.

This article argues that the protective purpose theory, by grounding the assessment of recoverable contractual damages in the purpose and scope of protection of the contract itself, more faithfully embodies the principles of freedom of contract and risk allocation, and more effectively gives effect to private autonomy. This approach not only produces more appropriate results in individual cases, but also exhibits greater coherence and persuasiveness at the theoretical level. Accordingly, the limitation of recoverable damages in Taiwanese contract law should primarily be based on the protective purpose theory, rather than continuing to treat the doctrine of adequate causation as the general standard. The doctrine of adequate causation should instead function as a subsidiary criterion under the protective purpose framework, assisting in delineating the boundaries of contractual protection, so as to better align with the institutional characteristics and normative objectives of contract law.