Is fire the greatest invention of civilization?

Man is the only creature that can deliberately create fire to do work for him. It allowed cooking of food, and then later when torches, lanterns and such were created, it brought light into the darkness, and extended the time that mankind could be out tending flocks, fields etc.

As man discovered different types of fuels (wood, peat, oil, nuclear) more and more people could be supported on less land. With it, we can create all kinds of things, including metals, plastics, etc.

Sometime soon, mankind will master the power of the sun, fusion energy (controlled, of course!)