Give him threepence, since he must make a gain out of what he learns.
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 line is length without breadth.
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.
And the whole is greater than the part.