读书人的留学英语作文：论说文的主题
谢振礼老师 ielts360toefl@163.com
Thesis statements (in the introduction) must make a claim or argument. They are opinions, not statements of fact.
留学考试的论说文一定要在引言中申论主题。这个主题就是你答题的立场或观点。所以主题是你个人的意见。不过，你个人的意见不是你说了就算，你要举出理由，例子，细节来解释并支持你答题的立场。
你写论说文的时候，心中要企图让读者(考官)既欣赏又接受你的意见。英文作文高分的能耐是你先要锻炼作文的逻辑思维，同时你还要学习地道的英文表达。鼓励网友考前多读多写多改多运气。
文章开头的主题一定不要写出无须争论的事实，因为事实没有必要经过(提出理由，例子，细节)论证。因此一旦你误解主题的特性，那就造成错误第一步，造成你在中体段落中无法发展内容。所以学术性的论说文，每一篇都有一个值得议论的主题来贯彻全文的起承转合。
来龙去脉，起承转合--全文都是主题的游戏。游戏的规则：引言要申论主题，中体要支持主题，结尾要重申主题。
学术派的写作有一套对于主题的说法。以下两段来自美国普度大学的在线写作实验室。第一段为主题下定义。第二段补充强调主题的范围必须缩小成为焦点。有焦点的主题才有比较深度的内容，而却不会跑题。
Purdue OWL (Online Writing Lab.): 普度大学 猫头鹰
主题的定义：
"An argumentative or persuasive piece of writing must begin with a debatable thesis or claim. In other words, the thesis must be something that people could reasonably have differing opinions on. If your thesis is something that is generally agreed upon or accepted as fact, then there is no reason to try to persuade people."
主题要缩小：举例说明
The thesis needs to be narrow:
"Although the scope of your paper might seem overwhelming at the start, generally the narrower the thesis, the more effective your argument will be. Your thesis or claim must be supported by evidence. The broader your claim is, the more evidence you will need to convince readers that your position is right."
--主题太宽大的例子，有缩小的必要--Example of a thesis that is too broad:
Bad>Drug use is detrimental to society.
--经过缩小范围的主题有焦点--Example of a narrow or focused thesis:
Better>Illegal drug use is detrimental to society because it usually encourages gang violence.
