The Art of Public Speaking by Dale Carnegie

Training in public speaking is not a matter of externals--primarily; it is not a matter of imitation--fundamentally; it is not a matter of conformity to standards--at all. Public speaking is public utterance, public issuance, of the man himself; therefore the first thing both in time and in importance is that the man should be and think and feel things that are worthy of being given forth. Unless there be something of value within, no tricks of training can ever make of the talker anything more than a machine--albeit a highly perfected machine--for the delivery of other men's goods. So self-development is fundamental in our plan.