Wherever there are qualities there are likewise quantities, but not always vice versa.

If you don't execute on your plans, then you don't reach anywhere.

Chase your dreams .... but make sure you don't find shortcuts.

The Earth is round, and is inhabited on all sides, is insignificantly small, and is borne through the stars.

Eyesight should learn from reason.

Astronomy would not provide me with bread if men did not entertain hopes of reading the future in the heavens.

I am a Lutheran astrologer, I throw away the nonsense and keep the hard kernel.

Nature uses as little as possible of anything.

I believe only and alone in the service of Jesus Christ. In him are all refuge and solace.

When ships to sail the void between the stars have been built, there will step forth men to sail these ships.

If the earth should cease to attract its waters to itself all the waters of the sea would be raised and would flow to the body of the moon.

Truth is the daughter of time, and I feel no shame in being her midwife.

God is the kind Creator who brought forth nature out of nothing.

O telescope, an instrument of much knowledge, more precious than any sceptre!

Once miracles are admitted, every scientific explanation is out of the question.

Geometry is the archetype of the beauty of the world.

Without proper experiments, I conclude nothing.

Nature loves simplicity and unity.

Where there is matter, there is geometry.