传统的知识定义被认为是JTB理论，即知识是确证的真信念（justified true believe），这一定义要求知识要满足三个条件：真值条件，信念条件和确证条件。但盖梯尔在1963年发表的论文《确证的真信念是知识吗》中提出了两个反例，表明这三个条件可能是知识的必要条件，但并不是知识的充分条件。大部分哲学家承认了这两个反例的作用，并对这一盖梯尔问题展开了广泛而持久的探讨。 本文的第一部分介绍了传统的知识定义，并说明盖梯尔问题是对知识定义的重新构造和思考的问题，并不是只局限于盖梯尔自己的反例。我们应当注意到，正是盖梯尔的论文把对知识论或认识论的研究从关注认识的起源、范围和有效性的问题转移到有关知识的定义、条件和确证性问题。 盖梯尔问题提出后，不断有哲学家尝试对其做出解答，他们的解答又不断被新的反例所推翻，尽管这些反例并不是由盖梯尔本人所提出的，但也同样被称为盖梯尔反例而被纳入盖梯尔问题之中。其中有些反例的形式已和最初的盖梯尔反例有所不同，但所有的反例都直指一个核心问题，即知识的确证问题。本文的第二部分就是通过梳理一个个的反例来介绍不同的对盖梯尔问题的解答，并进而找到反例的一般形式，从而解决盖梯尔问题。 本文的最后一部分展示了笔者对诸种反例的一般形式的见解，并根据这种一般形式，尝试提出一种新的知识定义。

Traditional definition of knowledge is considered as the JTB theory that knowledge is justified true believe, this definition requires knowledge to satisfy three conditions: truth conditions, conditions of belief, and confirmed conditions. But two counter-examples were proposed in Gettier’s published thesis in 1963 “ Is justified true believe knowledge? ” which indicated that the three conditions may be necessary but not sufficient condition of knowledge. Most philosophers recognized the role of the two opposite cases, and probed Gettier problem in a broad and lasting range. In the first part of this paper, the traditional definition of knowledge is introduced, and Gettier problem is explained as knowledge-definition’s re-construction and reflection, not only confined to Gettier’s own counter-examples. We should note that it is Gettier’s paper which changed the research of knowledge from a focus on understanding the origin, scope and effectiveness of the problem to the definition of knowledge, conditions and confirmation issues. After Gettier problem proposed, there have been many philosophers trying to give their answer, and their answers had been overthrown by the new counter-examples continuously. Although these counter-examples were not proposed by Gettier himself, they were also known as Gettier counter-examples and incorporated into the Gettier problem. Some counter-examples form is different from the initial, but all cases are directed against a core issue, which is “the issue of knowledge justification”. The last part of the paper display the author’s opinion on general forms of various counter-examples, and according to the general forms, a new definition of knowledge is tried to be proposed.