The most successful men in ...

The most successful men in the end are those whose success is the result of steady accretion. It is the man who carefully advances step by step, with his mind becoming wider and wider - and progressively better able to grasp any theme or situation - persevering in what he knows to be practical, and concentrating his thought upon it, who is bound to succeed in the greatest degree.
 Alexander Graham Bell

Quotes from the same author

When one door closes, another opens; but we often look so long and so regretfully upon the closed door that we do not see the one which has opened for us.
 Alexander Graham Bell
What this power is I cannot say; all I know is that it exists and it becomes available only when a man is in that state of mind in which he knows exactly what he wants and is fully determined not to quit until he finds it.
 Alexander Graham Bell
What this power is, I cannot say... All I know is that it exists.
 Alexander Graham Bell
The only difference between success and failure is the ability to take action.
 Alexander Graham Bell
I have heard articulate speech produced by sunlight I have heard a ray of the sun laugh and cough and sing! … I have been able to hear a shadow, and I have even perceived by ear the passage of a cloud across the sun's disk.
 Alexander Graham Bell