In an idyllic world, speech is the tool to give expression to your thoughts. In a professional world, speech is a tool to make others act the way you want. By logical extension, speech is a tool of power, a double-edged sword that can win a battle but can also hurt the wielder if used without skill. It is extremely necessary to learn how to make skillful use of speech and make a persuasive presentation. Whether in a court-battle, or in a sales transaction, the same principles hold true.