Comment by andsoitis

There's of course no single correct list, but I would pick: language (symbolic communication), writing, the scientific method, electricity, the computer.

Other highly consequential inventions: the printing press, the wheel, agriculture, money, the internet.

Notice something subtle. Early inventions extend coordination. Middle inventions extend memory. Later inventions extend reasoning. The latest inventions extend agency. This suggests that human history is less about tools and more about outsourcing parts of the mind into the world.