Now art is a principle of movement in something other than the thing moved, nature is a principle in the thing itself (for man begets man), and the other causes are privations of these two.

• 技术之为动变原理出于被动变事物以外之另一些事物，自然之为动变原理则出于事物本身（如人生人），其它的原因则为两者之阙失。