Earth, water, air and fire

From Eureka The Birth of Science by Andrew Gregory:

The philosopher Empedocles of Acragas introduced the four elements of earth, water, air and fire, which were to become standard in Greek thought. These should not be understood as literally earth, water, and so on, but in a slightly more abstract manner as solid, liquid, gas and fire or as principles of solidity, fluidity, gasesousness and fieriness. (pg. 28)

Some things not new but worth reviewing and remembering:

• Logic is about finding the correct form of an argument not the correct content of it
• Empeiria is skill to do something whereas episteme is knowledge of why it occurs