An astronomer must be cosmopolitan, because ignorant statesmen cannot be expected to value their services

And when statesman or others worry [the scientist] too much, then he should leave with his possessions.

Behold, directly overhead, a certain strange star was suddenly seen . . . Amazed, and as if astonished and stupified, I stood still

When I had satisfied myself that no star of that kind had ever shone before, I was led into such perplexity by the unbelievability of the thing that I began to doubt the faith of my own eyes.

Those who study the stars have God for a teacher.

Now it is quite clear to me that there are no solid spheres in the heavens, and those that have been devised by the authors to save the appearances, exist only in the imagination.

When, according to habit, I was contemplating the stars in a clear sky, I noticed a new and unusual star, surpassing the other stars in brilliancy . . . . There had never before been any star in that place in the sky.

So mathematical truth prefers simple words since the language of truth is itself simple.

May I not seem to have lived in vain.

And when statesmen or others worry him [the scientist] too much, then he should leave with his possessions. With a firm and steadfast mind one should hold under all conditions, that everywhere the earth is below and the sky above and to the energetic man, every region is his fatherland.

The mouse is wise, but the cat is wiser.

There is something eccentric in the orbit of Mars.

It was not just the Church that resisted the heliocentrism of Copernicus.

From his observations, he concluded that it [Tycho's supernova] was not some kind of comet or a fiery meteor, whether these be generated beneath the Moon or above the Moon, but that it is a star shining in the firmament itself - one that has never previously been seen before our time, in any age since the beginning of the world.