For the engineers out there.

How do a mathematician, a physicist, and an engineer determine the volume of a red rubber ball?

The mathematician measures the circumference and applies the formula for the volume of a sphere.
The physicist immerses the ball in a beaker filled with water and measures the amount of displacement.
The engineer looks it up in his book of red rubber ball values.

The question is not, Can they reason? nor, Can they talk? but, Can they suffer?
~Jeremy Bentham