Obstacles cannot crush me. Every obstacle yields to stern resolve. He who is fixed to a star does not change his mind.
Once you have flown, you will walk the earth with your eyes turned skyward; for there you have been, there you long to return.
Common Sense is that which judges the things given to it by other senses.
Iron rusts from disuse, stagnant water loses its purity, and in cold weather becomes frozen, even so does inaction sap the vigors of the mind.
Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous.
He who is fixed to a star does not change his mind.
All our knowledge has its origins in our perceptions.
Just as iron rusts from disuse, even so does inaction spoil the intellect.
Every now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer. Go some distance away because then the work appears smaller and more of it can be taken in at a glance and a lack of harmony and proportion is more readily seen.
Iron rusts from disuse; water loses its purity from stagnation ... even so does inaction sap the vigour of the mind.