The organ of perception acts more readily than judgment.

I have always felt it is my destiny to build a machine that would allow man to fly.

Inaction saps the vigor of the mind.

Even the richest soil, if left uncultivated will produce the rankest weeds.

You should prefer a good scientist without literary abilities than a literate one without scientific skills.

There is no object so large but that at a great distance from the eye it does not appear smaller than a smaller object near.

You grow in reputation like bread in the hands of a child.

Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.

The merit of painting lies in the exactness of reproduction. Painting is a science and all sciences are based on mathematics. No human inquiry can be a science unless it pursues its path through m a t h e m a t i c a l e x p o s i t i o n a n d demonstration.

The mole has very small eyes and it always lives under ground; and it lives as long as it is in the dark but when it comes into the light it dies immediately, because it becomes known; and so it is with lies.