厘清情势变更制度与合同法相关制度之边界

Clarification of boundary of rebus sic stantibus and related system of contract law

情势变更制度与合同法体系内的重大误解、显失公平、不可抗力、法定解除等相关制度易发生混淆。通过案例分析并运用民法解释学的方法,得出以下结论:情势变更制度与因重大误解而可变更、可撤销制度存在竞合可能,与因显失公平而可变更、可撤销制度差别显著;情势变更与不可抗力易混淆的原因在于依大情势说情势变更包含不可抗力;"小情势"-商业风险+政策法律变动≈司解二第26条界定的情势变更;情势变更制度与法定解除制度中的"不能实现合同目的"涵义相同。

Rebus sic stantibus is prone confused with major misunderstanding,unconscionability,Force majeure and statutory dissolution in the system of contract law.Through case analysis and the use of civil law hermeneutics,the author draw the following conclusion： Rebus sic stantibus and the system of alterable or voidable contract,may be overlapping of laws if the latter due to major misunderstanding,and make a great difference if the latter due to unconscionability;It is difficult to distinguish rebus sic stantibus and force majeure,the reason is that rebus sic stantibus includes force majeure according to ＂doctrine of huge situation＂.＂miniscule situation＂-business risk＋policy legal changes≈statutory rebus sic stantibus;Rebus sic stantibus and statutory dissolution has the same meaning on ＂frustration of contract＂.