The Mill-Mill Argument

The Mill-Mill Argument debates whether a machine, like a watermill, is made of smaller machines or parts. If a watermill is just a machine built from smaller parts, then those parts are also machines made from even smaller parts, and so on. But this leads to an infinite regress—an endless chain of smaller parts—making it impossible to identify a true "first" machine. Mill argued that there must be a primary, simple machine (like a basic waterwheel) that isn’t just made of smaller parts, to stop the infinite regress and explain how complex machines begin to function.