How do I define success? Let me tell you, money's pretty nice. But having a lot of money does not automatically make you a successful person. What you want is money and meaning. You want your work to be meaningful, because meaning is what brings the real richness to your life.
I can think of nothing more soul destroying in life than to persist in trying to do a thing you want desperately to do well, and to know that you are at the best second rate.
Edison was by far the most successful and, probably, the last exponent of the purely empirical method of investigation. Everything he achieved was the result of persistent trials and experiments often performed at random but always attesting extraordinary vigor and resource. Starting from a few known elements, he would make their combinations and permutations, tabulate them and run through the whole list, completing test after test with incredible rapidity until he obtained a clue. His mind was dominated by one idea, to leave no stone unturned, to exhaust every possibility.