Russell H. Conwell 
The Key to Success [EPUB ebook] 

This book is sent out to induce people to look at their own eyes, to pick up the gold in their laps, to study anatomy under the tutorship of their own hearts. One could accumulate great wisdom and secure fortunes by studying his own finger-nails. This lesson seems the very easiest to learn, and for that reason is the most difficult.
My hope is by this means to reach a larger audience even than that which has heard some of the things herein so many times in the last forty-five years. We do not hope to give or sell anything to the reader. He has enough already. But many starve with bread in their mouths. They spit it out and weep for food. Humans are a strange collection. But they can be induced to think much more accurately and far more efficiently. This book is sent out as an aid to closer observation and more efficient living.