译文（字数 3311）：

合同效力来源于合同的无效要素

杜鲁，奥耶卡其·威兹德姆·凯撒

摘要

合同的无效要素是指使合同变无效或者可撤销的技术术语。无效合同中这些无效要素的存在将会削弱合同的效力或者使合同无效。合同的无效要素如：过失、胁迫、虚假陈述、不正当影响和不法行为，这些都是合同效力的决定性因素。他们是一旦形成了，就能够影响合同效力的各种各样的因素。它的含义是：当无效要素不存在时，合同的有效性通常是不容置疑的。正是在这样的背景下，本文仔细研究了合同效力来源于合同的无效要素的相关问题。

外文原文（字符数 9119）：

VITIATING ELEMENTS OF CONTRACT AS A SOURCE OF

CONTRACTUAL VALIDITY

By

Duru, Onyekachi Wisdom Ceazar

Abstract

A ‘vitiating element of contract’ is the technical term for the things which make a contract void or voidable. Vitiating factors in a contract are those factors the existence of (any of) which will cripple or invalidate the contract. Vitiating elements of contract   such as mistake, duress, misrepresentation, undue influence and illegality, are determinants of the validity of a contract. They are the various factors which can affect the validity of a contract once it has been formed. The implication of which is that the validity of a contract is normally unquestioned when vitiating elements are absent. It is against this background that this essay has examined vitiating elements of contract as source of contractual validity.