The faculties are tools; the user of the tools is you, yourself; that in you which can cause you to use the tools in the right way, at the right time and in the right place is the cause of success.
the special faculties used in your work are the tools you use, but success does not depend alone on having good tools; it depends more on the power which uses and applies the tools.
The cause of success is some power within you; you have the power to develop any power to a limitless extent; for there is no end to mental growth; you can increase the strength of this power indefinitely, and so you can make it strong enough to do what you want to do, and to get what you want to get; when it is strong enough you can learn how to apply it to the work, and therefore, you can certainly succeed.
The cause of success is not in the environment of the individual, because if it were, all persons within a given radius would be successful, and success would be wholly a matter of neighborhood; and we see thatpeople whose environments are practically the same, and who live in the same neighborhood show us all degrees of success and failure; therefore, we know that the cause of success must be in the individual, and nowhere else.
The cause of success is always in the person who succeeds; you will see that this must be true, because if the cause of success were in nature, outside the person, then all persons similarly situated would succeed.