Accidental plagiarism usually occurs because we do not understand the cultural conventions of academic writing and citation. In most western countries, and certainly in the United States, there is a very real sense that writers own their ideas and the words they use to express those ideas. As John R. Edlund explains in “What Is ‘Plagiarism’ and Why Do People Do It?”:
There are two important factors that must be understood in order to understand American concepts of plagiarism. First, in the English-speaking world, people believe that ideas and written expressions of ideas can be owned. When an author writes down a particular set of words and phrases expressing a specific idea, this author in effect owns those words and that idea. Therefore to use these words without giving the author credit is to steal them. This is very different, for example, from the Chinese idea that words and ideas belong to the culture and the society and should be shared by all individuals (Myers 11). Second, Americans believe that writing is a visible, concrete demonstration of a writer's knowledge, insight, and academic skill. Thus, to represent another person's writing as your own is to misrepresent your own accomplishments. This is a type of fraud or deception. [Italics and boldface added] http://www.calstatela.edu/centers/write_cn/plagiarism.htm (14 Jan. 2004).
意外剽窃通常由于我们不理解学术写作和引用的文化惯例时发生。在大多数西方国家，特别是美国，有非常真实的关于作者拥有他们思想及表述那些思想的所使用文字的意识。如John R. Edlund在“什么是‘剽窃’以及人们为什么剽窃？”中解释的：为理解美国剽窃概念，必须理解有两个重要因素。第一，在说英语的国家，人们认为思想和思想的书面表述可以被拥有。当作者写下一些特别的文字和段落以表达一个特殊的思想时，该作者实际上拥有这些文字和思想。因而使用这些文字而给予作者荣誉就是偷窃了它们。这是非常不同的，例如，中国的观念，文字和思想属于文化和社会并且应该被所有人分享（Myers 11）。第二，美国人相信写作是看得见的，实在的作者的知识、见解和学术技能的体现。所以，将他人的写作作为你自己的是错误呈现你自己的造诣。这是一种欺骗或诡计。

谢谢提供线索，并且帮助翻译。不过非常遗憾，您提供的链接，page not found。如文中所述，不同文化对知识产权的理解是不同的。中国人对权利本身都比较模糊，我与他人的界限不清楚。对于他人的文字，也不够尊重。但是对于纯粹的文抄公，古人也是鄙视的。相反的情况倒是有，比如有人自己写了书，却假托古人。