Whenever you write a speech, lecture or presentation, apply the “less is more” principle. In general, the simpler your words are, the more your audience — no matter how sophisticated it is — will understand. And the shorter your talk, the more likely you will be to maintain your audience’s attention to the end. Two memorable speeches that incorporated the “less is more” principle: The Gettysburg Address. Delivered by President Lincoln on Nov. 19, 1863, to dedicate Soldiers’ National Cemetery in Gettysburg, Pa., the address was short — perhaps because Lincoln had not been invited as the main speaker. Instead,…