Astronomy is written for astronomers

If there be some who, though ignorant of all mathematics . . . dare to reprove this work, because of some passage of Scripture, which they have miserably warped to their purpose, I regard them not, and even despise their rash judgement.

More stars in the north are seen not to set, while in the south certain stars are no longer seen to rise.

Moreover, since the sun remains stationary, whatever appears as a motion of the sun is really due rather to the motion of the earth.

To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge.

Pouring forth its seas everywhere, then, the ocean envelops the earth and fills its deeper chasms.

I am aware that a philosopher's ideas are not subject to the judgment of ordinary persons, because it is his endeavour to seek the truth in all things, to the extent permitted to human reason by God.