That, if a straight line falling on two straight lines makes the interior angles on the same side less than two right angles, the two straight lines, if produced indefinitely, meet on that side on which the angles are less than two right angles.

A prime number is one (which is) measured by a unit alone.

Sire, there is no royal road to geometry.

And the whole is greater than the part.

Things which are equal to the same thing are also equal to one another.

The laws of nature are but the mathematical thoughts of God.

A line is length without breadth.