Few people are lacking in ...

Few people are lacking in capacity, but they fail because they are lacking in application.
Few people are lacking in capacity, but they fail because they are lacking in application.

Quotes from the same author

Knowledge comes, but wisdom lingers. It may not be difficult to store up in the mind a vast quantity of facts within a comparatively short time, but the ability to form judgments requires the severe discipline of hard work and the tempering heat of experience and maturity.
I have never been hurt by anything I didn't say.
We identify the flag with almost everything we hold dear on earth, peace, security, liberty, our family, our friends, our home. . .But when we look at our flag and behold it emblazoned with all our rights we must remember that it is equally a symbol of our duties. Every glory that we associate with it is the result of duty done.
Patriotism is easy to understand in America. It means looking out for yourself by looking out for your country.
Because of what America is and what America has done, a firmer courage, a higher hope, inspires the heart of all humanity.