The weakest living creature, ...

The weakest living creature, by concentrating his powers on a single object, can accomplish something. The strongest, by dispensing his over many, may fail to accomplish anything. The drop, by continually falling, bores its passage through the hardest rock. The hasty torrent rushes over it with hideous uproar, and leaves no trace behind.
The weakest living creature, by concentrating his powers on a single object, can accomplish something. The strongest, by dispensing his over many, may fail to accomplish anything. The drop, by continually falling, bores its passage through the hardest rock. The hasty torrent rushes over it with hideous uproar, and leaves no trace behind.

Quotes from the same author

Permanence, perseverance and persistence in spite of all obstacles, discouragements, and impossibilities: It is this, that in all things distinguishes the strong soul from the weak.
Silence is deep as Eternity; Speech is shallow as Time.
This world, after all our science and sciences, is still a miracle; wonderful, inscrutable, magical and more, to whosoever will think of it.
Instead of saying that man is the creature of circumstance, it would be nearer the mark to say that man is the architect of circumstance.
Do not be embarrassed by your mistakes. Nothing can teach us better than our understanding of them. This is one of the best ways of self-education.