Napoleon Hill, author and one of the earliest recognized personal success experts, had a basic message for his students: Anyone can become rich, and you ought to stop thinking of wealth as tied purely to money or reputation.
That became the driving thesis behind his best-selling book Think and Grow Rich,which has sold more than 70 million copies worldwide since its publication in 1937. Hill, who also served as an adviser to former U.S. President Franklin D. Roosevelt, famously wrote: "Anything the mind of man can conceive and believe, it can be achieved."
A new book, Your Right to Be Rich, due in September from Penguin Random House, synthesizes Hill's most influential lectures in print, outlining them according to his 17 guiding "success principles."
Ahead of the book's release, check out some of Hill's best quotes of all time:

1. On having definiteness of purpose 

"If you want the mind to pick up an idea and to form a habit so that the mind will automatically act upon that idea, you've got to tell the mind what you want, over and over and over again."

2. On developing mastery

"Whatever it is that you lack in education, or knowledge, or influence, you can always obtain it through somebody who has it. Exchange of favors and exchange of knowledge is one of the greatest exchanges in the world."

3. On applying faith

"The subconscious mind only knows what you tell it, or what you allow other people to tell it, or what you allow the circumstance of life to tell it ... it accepts the things that you send over, and if you send over predominating thoughts on poverty and ill health and failure, that's exactly what you'll get."

4. On going the extra mile

"I don't know of any one quality or trait that can get a person an opportunity quicker than to go out of his way or her way to do somebody a favor, or do something useful."

5. On having a pleasing personality 

"Don't take it too seriously, no matter what it is. During the Depression, I had four of my friends commit suicide. Two of them jumped off tall buildings, one shot himself, and another one took poison. They did it because they lost all their money. I lost twice as much as they did, but I didn't jump off any building, I didn't shoot myself, I didn't poison myself ... My mental attitude toward it was to start immediately looking for that seed of improvement."

6. On having initiative

"You don't have to be very brilliant. You don't have to have such a wonderful education. You can be an outstanding success if you will only take what little you have, whether it's little or much, and start using it, putting it into operation, doing something about it, and doing something with it. And, of course, that calls for initiative."

7. On having a positive attitude

"Hoping is better than wishing. Because the difference between a hope and a wish is that hope is a beginning to take on faith."

8. On being self-disciplined 

"Be careful what you set your heart upon because, if you set your heart on anything and stand by that decision, you're going to get it."

9. On being enthusiastic

"If you want to do something, work yourself into a state of wild enthusiasm and go to work where you stand, even if it's nothing more than drawing a picture in your mind of the thing you want to do, and keep drawing that picture, making it more vivid all the time." 

10. On creating controlled attention

"Concentration requires a definiteness of purpose in such proportion that it becomes an obsession. There's no use of having a motive unless you put obsession of desire or obsession of purpose in back of it."

11. On thinking accurately 

"The truth of the matter is that your emotions are not reliable at all. The emotion of love, for instance, is the greatest and the grandest of all the emotions, and yet it can also be the most dangerous. More trouble in human relationships grows out of misunderstanding the emotion of love than all other sources of difficulty combined."

12. On learning from adversity 

"One of the best things that can happen to you is to meet with problems, circumstances, and incidents that force you to think, because without a motive, you might not do much thinking anyway." 

13. On fostering cooperation

"Being recognized for personal initiative, a pleasing personality, or outstanding work is a strong motive to inspire cooperation. Give a person recognition when he does a good job; say so, and do something about it."

14. On imagination

"Just think of all the things the mind of man has brought forth to introduce people to one another."

15. On the importance of health

"You can't have good health, prosperity, happiness, or peace of mind if you're going to fear anything--even death, most of all. Personally, I'm looking forward to death with great anticipation. It's going to be one of the most unusual interludes of my whole life."

16. On budgeting time and money

"Set aside a definite amount for investment, even if it's only as small as a dollar a week or even 50 cents a week. It's not the amount that's important, it's the habit of being resourceful and frugal."

17. On the "law of cosmic habit force"

"Man is not bound by instinct; man is bound only by the imagination and the willpower of his own mind."