Final answer:
The statement that earth, air, fire, and water are the only substances that exist; everything else exists in name only is False.
Step-by-step explanation:
The statement that earth, air, fire, and water are the only substances that exist; everything else exists in name only is False. While the ancient Greeks believed that the four elements (earth, air, fire, and water) were the basic substances that made up everything in the universe, this idea has been proven incorrect. Modern science has revealed that matter is composed of atoms, which are made up of various combinations of different elements, not just the four ancient elements.