The two operations of our understanding, intuition and deduction, on which alone we have said we must rely in the acquisition of knowledge. – Rene Descartes
When it is not in our power to follow what is true, we ought to follow what is most probable. – Rene Descartes
I am indeed amazed when I consider how weak my mind is and how prone to error. – Rene Descartes
Nothing in this world can take the place of persistence. Talent will not nothing is more common than unsuccessful people with talent. Genius will not unrewarded genius is almost a proverb. Education will not the world is full of educated failures. Persistence and determination alone are omnipotent. – Calvin Coolidge