选好演讲的题目，下一步就要确定该题目所包含的范围，并且做到不越雷池半步。可别妄想去讲一个包容万千的话题，那真是徒劳而无益的事情。有一个年轻人想讲两分钟，可是定了一个题目《公元前500年的雅典战争》，这简直就是痴人说梦话。他才讲完雅典城的建造，时间就到了。他想在一场谈话中包含太多的东西，最终只能以演讲失败而告终。当然这是个极端的例子。我曾听过许多讲演，都因为范围不确定，结果因同样的原因——涵盖太多的内容和论点，从而无法抓住听众的注意力。为什么会这样呢？因为人的注意力不可能一直跟随一连串单调的事实。如果你的讲演听起来像是世界年鉴，你就根本无法抓住听众的注意力很久。选个简单的题目，例如《黄石公园之旅》之类的，那么多数讲演者都会十分热心的，对于园中每个景色都想说上一些，不肯遗漏半点东西。这样听众就会被带着，漫天遍地，由这一点奔至另一点。最后，能够记住的，只是些模糊的瀑布、山岭和喷泉。如果讲演者把自己限定在公园的某一方面，例如野生动物或是温泉，这场演讲该会变得多么令人难以忘怀啊！这样，在演讲中便可以有时间描绘生动的细节，使得黄石公园以鲜明的颜色与无穷的变化栩栩如生地展现于听众的眼前。Once you have selected your topic, the first step is to stake out the area you want to cover and stay strictly within those limits. Don't make the mistake of trying to cover the open range. One young man attempted to speak for two minutes on the subject of "Athens from 500 B.C. to the Korean War." How utterly futile! He barely had gone beyond the founding of the city before he had to sit down, another victim of the compulsion to cover too much in one talk. This is an extreme example, I know; I have heard thousands of talks,less encompassing in scope, that failed to hold attention for the same reason-they covered far too many points. Why? Because it is impossible for the mind to attend to a monotonous series of factual points. If your talk sounds like the World Almanac you will not be able to hold attention very long. Take a simple subject, like "A Trip to Yellowstone Park." In their eagerness to leave nothing out, most people have something to say about every scenic view in the Park. The audience is whisked from one point to another with dizzying speed. At the end, all that remains in the. mind is a blur of waterfalls, mountains,and geysers.How much more memorable such a talk would be if the speaker limited himself to one aspect of the Park, the wildlife or the hot springs, for example. Then there would be time to develop the kind of pictorial detail that would make Yellowstone Park come alive in all its vivid color and variety.

这个道理用于任何题目都准，不管它讲的是销售术、烤蛋糕、减免税赋或者是飞弹。开始之前，先加以限制和选择，把题目缩小至某一个范围内，以便适合自己讲演的时间。This is true of any subject, whether it be salesmanship, baking cakes, tax exemptions, or ballistic missiles. You must limit and select before you begin, narrow your subject down to an area that will fit the time at your disposal.

在短短的不超过五分钟的讲演里，只能期望说明一两点而已。就算30分钟的讲演中，演讲者若是想包含四或四个以上的主要概念，也是很少能够成功的。In a short talk, less than five minutes in duration, all you can expect is to get one or two main points across. In a longer talk, up to thirty minutes, few speakers ever succeed if they try to cover more than four or five main ideas.